Thomas Say (1787–1834) based his description of the ammonite species Baculites ovata (= B. ovatus) on a single specimen in the collection of his childhood friend, the Quaker naturalist Reuben Haines III (1786–1831). However, the specimen's whereabouts faded from memory after Haines and Say both died unexpectedly in the early 1830s. The holotype specimen has been missing for more than 180 years, and was thought to be lost or destroyed until 2017, when I relocated it at Haines's ancestral home (Wyck) in Philadelphia, Pennsylvania, where his collection was preserved by his descendants in its original wooden cabinet. Herein, I present the first photographic images, an illustration of its suture line, and quantitative measurements for use by systematic paleontologists.

New material from the Upper Devonian (Famennian) Catskill Formation of Pennsylvania, USA, reveals anatomical details previously lacking from the enigmatic fossil species that Newberry (1889, U.S. Geological Survey Monograph 16:1–228) named Holoptychius ? radiatus. The original material (scales and lepidotrichia) was attributed to Holoptychius (Sarcopterygii, Porolepiformes) according to the ridged ornament on the exposed portion of the scales. Scale and cranial anatomy revealed by the new material supports a reassignment of the species to Langlieria (Sarcopterygii, Tristichopteridae). The emended diagnosis of the new combination includes the grooved scale ornament that was noted, though described differently by Newberry, and a posterior oblique pitline groove of the parietal that extends to the caudal margin of the element. Along with Hyneria lindae and Eusthenodon sp. indet., there are now at least three known species of Tristichopteridae from the Catskill Formation. Temporal/spatial separation of these species, along with supporting anatomical characteristics, suggests that tristichopterids commonly filled the ecological niche of top predator in the Famennian-age nonmarine ecosystems of the Catskill Delta Complex. The presence of a Langlieria species in the Catskill Formation lends further support to a biogeographic connection between Pennsylvania, USA, and Belgium during the Famennian Stage of the Upper Devonian.

Alvin R. Cahn (1892-1971) was Professor of Zoology at the University of Illinois and latterly worked in conservation for the Tennessee Valley Authority. In the years following World War II he was on the staff of Allied General Headquarters in Tokyo, where he produced several major reports on mollusks. This paper focuses on his GHQ career and in particular his relationship with Tokubei Kuroda (1886-1987), the most important Japanese malacologist of the 20^th century.

Our understanding of pathological conditions is usually centered on human and domesticated species. Thus, a vast array of pathologies within vertebrates are unknown, especially those that occur in exotics and those that lack external characters, such as conditions that affect the skeleton. Exotics represent a majority of the vertebrates housed in zoos and other wildlife centers, and in the larger picture of conservation, represent the best way to determine potential health threats and cures for endangered and threatened species in the wild. Here we describe a case of acromegaly, a rare condition of excess growth hormone, in a hog badger (Arctonyx collaris) based on Computed Tomography (CT). This is the first documented occurrence of this condition in non-human or non-domesticated mammals, and the first occurrence within Mustelidae. The recognition of this rare condition within a badger suggests that acromegaly may be more widespread within mammals than previously thought, and has implications for diagnosis of other exotics within zoos.

A capybara jaw (Rodentia, Caviidae, Hydrochoerinae) and an isolated lower tooth fragment were recovered from dredge spoils on Pelican Island in Galveston Bay, Gulf Coast of Texas. The attached matrix on the jaw and most of the dredged material is clay, indicative of the latest Pleistocene Beaumont Formation which underlies the Holocene deposits. In the latest Pleistocene (Rancholabrean) of the United States, capybaras are known from along the Gulf and Atlantic coasts in Texas, Florida, Georgia, South Carolina, and Virginia.These Rancholabrean capybaras have been assigned to three different taxa: Neochoerus pinckneyi Hay, 1923 for the largest size specimens, Hydrochoerus holmesi Simpson, 1928 for the somewhat smaller specimens, or Neochoerus aesopi Leidy, 1853, a name that had been considered invalid because it was not adequately diagnosed, if there is only one late Pleistocene species of North American capybara.

The p4 in the new Texas mandible is much smaller than the genotype of N. pinckneyi from the Aransas River in South Texas and similar in size to H. holmesi from the Pleistocene of Florida and Recent H. hydrochaeris. However cheek tooth size and occlusal pattern in Recent capybaras varies significantly with age. Hydrochoerus holmesi cannot be distinguished from N. pinckneyi. None of the late Pleistocene capybaras of South Carolina, including the type and referred specimens of N. aesopi, have any characteristics to differentiate them from H. holmesi or N. pinckneyi. We therefore assign all the Texas and South Carolina specimens to N. aesopi.

A new species of peacock bass, Cichla cataractae, is distinguished from all congeners by molecular evidence and unique patterns of adult and juvenile pigmentation. Juveniles (<150 mm SL) have sides of body dominated by a series of three conspicuous dark blotches with the one below soft dorsal fin largest, attenuated posteriorly (long teardrop shape) but distinctly separated from elliptical caudal blotch; same blotches eventually with pale border (ocellated) in largest juveniles. Adult pattern on sides dominated by two distinct dark blotches, each one ocellated; anterior blotch rounded, located below anterior base of spinous dorsal fin and not extending above anterior lateral line; posterior blotch highly irregular in shape, located below soft dorsal fin and often displaced dorsally; additional dark blotch below posterior base of spinous dorsal fin generally absent or small, ocellated or not, and level with anterior blotch; vertical bars on sides generally absent or faint; postorbital stripe always present, highly broken into irregular series of dark spots, each one usually ocellated. Cichla cataractae is endemic to the Essequibo Basin where it typically inhabits rocky shoals in river channels with swift current. The new species is sympatric with the more widely distributed C. ocellaris, a species that prefers lentic habitats. Molecular analysis supports C. cataractae as a distinct lineage in a clade of Cichla containing C. temensis, C. melaniae, C. mirianae, C. piquiti and C. pinima. The oldest extant specimens of the new species were collected by Carl H. Eigenmann in 1908 and documented in his seminal "The Freshwater Fishes of British Guiana" (Eigenmann, 1912).

Long-term sediment accretion and nutrient concentrations were investigated in tidal marsh sediments of the Murderkill River, Delaware. Radionuclides (²¹⁰Pb and ¹³⁷Cs), stable isotopes (¹³C and ¹⁵N), organic matter concentrations and nutrient concentrations were measured. Tidal marsh sediment accumulation rates ranged from 0.10 to 0.20 g cm^-2 yr^-1, and accretion rates ranged from 0.31 to 0.74 cm yr^-1. The Carbon (C) to nitrogen (N) ratio (∼24) was higher in the downcore of upstream sites, and a similar C/N ratio was identified in surface sediment cores at the downstream sites. The sediment N concentration in the surface sediments was highest at the upstream sites (mostly ≥1% of N) and decreased downstream. Total nitrogen concentrations were highest from 1910 to 1920 (∼1.5% N), decreased to approximately 0.6% N by 1940, and then remained constant to present. The dominance of the C4 plant Spartina (cordgrass) over C3 plants after the 1940s may be due to an upward movement of saline water associated with hydrologic changes and a rise in relative sea level. Surface sediments in all of the cores have more total phosphorus (TP) than below ground. The downstream site closest to the estuary had an abrupt increase in surface TP (i.e., 0–10 cm). Sediment TP increased slightly from 2003 to present time (i.e., from 0.07 to 0.11% P). Sediment accumulation and accretion rates in the Murderkill River marshes are similar to the accretion rates determined by previous studies in the region.

A hypothesis of phylogenetic relationships is presented for species of the South American catfish subfamily Centromochlinae (Auchenipteridae) based on parsimony analysis of 133 morphological characters in 47 potential ingroup taxa and one outgroup taxon. Of the 48 species previously considered valid in the subfamily, only one, Centromochlus steindachneri, was not evaluated in the present study. The phylogenetic analysis generated two most parsimonious trees, each with 202 steps, that support the monophyly of Centromochlinae composed of five valid genera: Glanidium, Gephyromochlus, Gelanoglanis, Centromochlus and Tatia. Although those five genera form a clade sister to the monotypic Pseudotatia, we exclude Pseudotatia from Centromochlinae. The parsimony analysis placed Glanidium (six species) as the sister group to all other species of Centromochlinae. Gephyromochlus contained a single species, Gephyromochlus leopardus, that is sister to the clade Gelanoglanis (five species) + Centromochlus (eight species). Based on the new taxonomic arrangement herein, Balroglanis Grant 2015 and Sauronglanis Grant 2015 are placed in the synonymy of Centromochlus. Tatia is the most diverse genus within Centromochlinae, with twenty-six species in three monophyletic clades. The species composition of Tatia differs from that of Calegari et al. (2019). Duringlanis Grant 2015 and Ferrarissoaresia Grant 2015 are considered synonyms of Tatia. All generic taxa within Centromochlinae are diagnosed based on synapomorphic morphological characters. An identification key for Centromochlinae is provided.

Based on the examination of type and recently collected specimens, Moenkhausia lepidura madeirae Fowler is resurrected from the synonymy of M. intermedia and redescribed as a valid species. Moenkhausia madeirae can be diagnosed from all congeners by the following combination of characters: presence of two symmetrical dark blotches on caudal fin (one on each lobe), a conspicuous humeral blotch, 18-22 branched anal-fin rays, and mature males with two (rarely three) well-developed hooks on the last simple and first branched anal-fin rays, respectively. The species occurs in the middle and upper rio Madeira basin in Brazil and Bolivia. Comparisons are made with the other species of Moenkhausia presenting symmetrical dark blotches on the caudal-fin lobes, i.e., M. barbouri, M. bonita, M. dichroura, and M. intermedia.

The first collection of Oecetis inconspicua (Walker) (Trichoptera: Leptoceridae) from the Florida Keys (Monroe County, Florida) is reported. Specimens were collected from Flamingo Island (Marathon), Key Largo, and Long Key. This is the fifth caddisfly species known from the Florida Keys and the only species not in the family Hydroptilidae.

Five Gobio species viz. G. battalgilae, G. gymnostethus, G. hettitorum, G. insuyanus and G. microlepidotus inhabit the Konya endorheic basin. Some studies have suggested the synonymy of G. battalgilae and G. microlepidotus based on molecular characters. Therefore, this study aimed to test the hypothesis of synonymy of G. battalgilae and G. microlepidotus. Based on our results, the morphometric and meristic characters of G. battalgilae largely overlap with those of G. microlepidotus, and we find no evidence to support the distinctiveness of the two species. Therefore, G. battalgilae Naseka, Erk'akan & Küçük, 2006 is treated as a junior synonym of G. microlepidotus Battalgil, 1942.

The pimelodid genus Hypophthalmus is a small group of pelagic and planktivorous catfishes that are abundant and variously distributed in the lowland river basins of the Amazon, Parnaíba, Orinoco, Guianas and Paraná. Since their earliest published descriptions, commencing over 190 years ago with H. edentatus Spix and Agassiz 1829, the taxonomy and nomenclature of Hypophthalmus species have been confused and unresolved. In this study, four of the six available species names are validated and two new species are described. Newly discovered characters of the vertebral column, circumoral barbels, pelvic fins, and lateralis sensory canals provide strong support and diagnostics for species and species-groups. A key to species, anatomical descriptions, notes on identification of small juveniles and phylogenetic interrelationships are included. A lectotype is designated for Hypophthalmus marginatus and nominal Hypophthalmus longifilis, respectively.

Alburnus heckeli Battalgil 1944 is endemic to Lake Hazar in the Euphrates-Tigris River system (Persian Gulf basin) and shares morphological and molecular characters with the widespread species A. sellal Heckel 1843, except putatively for the number of gill rakers. This study compared morphometric and meristic data for A. heckeli with lentic and lotic populations of A. sellal. The only significant difference was in the number of gill rakers in lotic populations of A. sellal (10–25) vs. lentic populations of A. sellal (26–35) and A. heckeli (28–35). Although our results are consistent with the interpretation of A. heckeli and A. sellal as “young species”, the amiguity of available morphological and molecular sequence data suggest that A. heckeli is best treated as a junior synonym of A. sellal until reliable differences are found.

Alexander Wilson (1766–1813) based his description of the “Slate-colored Hawk / Falco atricapillus” (=Accipiter gentilis atricapillus) on a single specimen collected near Philadelphia, Pennsylvania, which he deposited for posterity in the Philadelphia (Peale) Museum. Wilson's illustration of the specimen was engraved and hand-colored prints were published in American Ornithology vol. 6 (1812b, Pl. 52) to accompany his scientific description of the species. However, the path of Wilson's type specimens became difficult to trace after the Peale Museum closed in 1846 and its collections were sold and dispersed. Wilson's holotype of F. atricapillus was presumed lost or destroyed until November 2020, when I rediscovered it in the collection of the Academy of Natural Sciences of Drexel University (ANSP), thanks to a penciled note made by the late Rodolphe Meyer de Schauensee, former ANSP curator of birds. This research also sheds new light on the history of the Peale Museum bird collection, exposing a basic misunderstanding about the “Peale numbers” cited by Wilson, which has broad implications for the history of American ornithology. In short, “Peale numbers” were assigned to species (not specimens) held in the Peale Museum.

A new species of Langlieria is described from the Upper Devonian (Frasnian) Irish Valley Member of the Catskill Formation. The type material was collected from a road cut exposure on the north side of the westbound lanes of Pennsylvania Route 322 west of Port Matilda, Centre County, Pennsylvania, U.S.A. The new species of Langlieria, the second from the Catskill Formation, is represented by high quality cranial material including parietal and postparietal shields, cheek, principal gular, and lower jaw; fin material; and body scales. The new species is the fourth tristichopterid to be described from the Catskill Formation (after Hyneria lindae, Langlieria radiatus, and Eusthenodon bourdoni) and the first from the Irish Valley Member. It is also the first species of Langlieria with a known record in the Frasnian. Sedimentological and stratigraphic data suggest that the discovery site represents a distal, tide-dominated location within the Catskill Delta system with a greater marine influence than has been reconstructed for the previously described Catskill Formation tristichopterids. A new phylogenetic analysis of Tristichopteridae is presented that is the first to include the new species of Langlieria described here and E. bourdoni from the Cogan House Exit Ramp locality (Famennian, Duncannon Member) along U.S. Route 15/Interstate 99. The 50% majority-rule consensus tree from the analysis supports a highly-nested clade of tristichopterids that includes all of the considered species from the Famennian, with the exception of Heddleichthys dalgleisiensis, and additionally includes the Frasnian Langlieria species that is described here.