274 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



basal margin and the nucleus is a prominent structural feature of all 

 known specimens. Circuli are relatively coarse (about 19 in 1 mm.). 

 On the covered portion of the scale the central ones are crescentic, 

 and paralleling the basal border are either sharply recurved or acutely 

 angulated as their courses approach the median sulcus. Peripherally 

 the circuli are more nearly longitudinal in their arrangement and 

 intersect in very acute angles the basal scale margin after only slight 

 median flexure. The exposed apical quadrant has a nuclear angle of 

 from 75° to 80° and is covered with short, sinuous circuli, which are 

 directed backward and slightly away from a faint median longitudinal 

 axis. 



Remarks: The scale characteristics of Paractichthys are more com- 

 parable to those of anacan thine fishes than to any other living group 

 (David, 1956). While very probably not closely related to any extant 

 member, all features exist in one or another genus of the Gadidae. 

 It is upon this basis that the family assignment has been made. 

 Heretofore, the codfishes and their allies have been recognized only 

 from marine sediments of Tertiary age. Paractichthys, thus, extends 

 the known geologic range of the gadid fishes into the upper Cretaceous, 

 and the genus may prove, on recovery of more complete remains, a 

 key to the establishment of the complete phyletic history of this dis- 

 tinctive assemblage of fishes. 



III. Comments on the Status of Cyclolepis stenodinus Cockerell 



Plate 3 



The genus Cyclolepis was named and described by Geinitz (1868). 

 The genotypic species, C. agassizi, is based on unassociated scales 

 from the Planer formation (Cenomanian and Turonian) of Saxony, 

 which display a subcircular or ovate outline with nearly central nu- 

 cleus, concentric circuli, and an absence of either radii or ctenoid 

 structures. Although various opinions have been held regarding the 

 affinities of the form, most current classification outlhies list Cyclolepis 

 with the salmonoid fishes (Romer, 1945; David, 1946). 



In 1919, Cockerell described an isolated scale from the upper 

 Maestrichtian (Fox Hills sandstone) of Colorado under the name 

 Cyclolepis stenodinus. The Cockerell type (USNM 8703) is exposed 

 in internal aspect, displaying prominent annular growth rings, and as 

 thus observed would appear to compare closely with the characteriza- 

 tion of Cyclolepis Geinitz. However, recent examination under highly 

 refractive liquids and the binocular microscope has revealed previously 

 unreported features of the embedded external surface of the scale. 

 The new information creates serious doubt as to the correctness of 

 the generic reference and even as to the validity of the Colorado 

 species. 



