24 PROCEEDINGS OF THE NATIONAL MUSEUM. 



elements. An outline of the cranial elements has already been given, 

 and a photograph of the complete specimen is given herewith to 

 correct some of the inaccuracies of Cope's original drawing. It 

 ought to be said, in justice to that brilliant author, that he did not see 

 the proofs of the article in whicli the form was described. A fuller 

 discussion and redescription of the species will be reserved. 



ICHTHYERPETON SQUAMOSUM Moodie. 



A remarkable form of amphibian was described « under this name 

 from material in the collection of the U. S. National Museum (Cat. 

 Xos. 447(), 4450). The species was only tentatively assigned to the 

 genus Ichthyerpeton Huxley. Its closer definition must await future 

 discoveries. It is, however, tJte only evidence of a completely .sc<(lcd 

 ampliihian Icnown from the (Utrhoniferous of North America. That 

 the specimens are amphibians and not fishes is evidenced in the well- 

 developed ventral scutellation. 



CTENERPETON ALVEOLATUM Cope. 



Plate 10. 



An examination of the type (Cat. No. 4475, U.S.N.M.) of this 

 peculiar form has not resulted in the discovery of any new characters. 

 A photograph is given in Plate 10 to correct Cope's original drawing, 

 which was inaccurate as to details. The form is interesting as fur- 

 nishing another illustration of the diversity of types assumed by the 

 ventral scutellation in the Carboniferous amphibians. In the genus 

 TiuUtmms no evidence has ever been detected of a ventral scutella- 

 tion, while in the genera Sauropleiira, /Saurerpeton, and Ctenerpeton 

 the scutellation of the abdomen has assumed a well developed and 

 characteristic form. 



PTYONIUS PECTINATUS Cope. 



Plate S, lis. B. 



There are four specimens of this species in the collection (Cat. 

 Nos. 4514, 4458, 4463, 44G4, U.S.N.M.) . The most perfect one, shown 

 on Plate 8, fig. 3, is interesting as giving an idea of the form of the 

 body, which Avas long, slender, and snake-like. In this specimen there 

 are no evidences of pectoral plates, although these are present on 

 a specimen of another species of this genus in the collection of the 

 American Museum of Natural History in New York City. The skull 

 of PtyoniuH is long and attenuated. The morphology of the skull 

 has not yet been determined, but it is hoped that this may be possible 

 from a close study of the material at hand, which includes six skulls 

 and various portions of the body. From the form of the vertebrae 



« Moodie. Journ. Geol., vol. 17, 1909, p. 69. 



