660 S. W. WILLISTON 



and Case, locate them among the Cotylosauria, and still use 

 the name Microsauria in its usually accepted sense. I can not 

 believe that the time has come for a new system of classification 

 and new names. 



LYSpROPHUS 



The history of the genus Lysorophus will be found in the vari- 

 ous papers of the appended list^^ and need not be recounted here. 

 Suffice it to say that Broili and others urge that it is a reptile; 

 while Broom and I believe it to be an amphibian closely allied 

 to, if not a member of the Urodela; Moodie thinks that it is a gym- 

 nophionian; and Case is confident that it is an amphibian, though 

 doubtful of its urodelan aflSnities. The question here at issue is : 

 Is Lysorophus a reptile? And, if so, to what group of the known 

 reptiles is it most nearly allied? Lysorophus is known to occur 

 in the Permocarboniferous of Illinois, Oklahoma and Texas. 

 My knowledge of the genus is based upon abundant material, 

 coming chiefly from the Clear Fork beds of northern Texas. 

 I would characterize the genus and group as follows : 



Lysorophus. Slender, Amphiuma-like in form; of from 8 

 or 10 inches to possibly 18 inches in length; with small limbs. 

 No pineal foramen; no lacrimal, postfrontal, postorbital, jugal 

 or quadratojugal bones; an unpaired supraoccipital bone, on 

 either side of which are two distinct bones, variously identifiable 

 as the squamosal and tabulare, or supratemporal; prefrontal 

 (lacrimal?) articulating with nasal, frontal and parietal; orbits 

 confluent with the open temporal region; quadrate ossified, 

 suturally united with squamosal, projecting downward and 

 forward; no temporal bars; palate with large subcranial plate, 

 probably the parasphenoid, or parasphenoid and basioccipital; 

 vomer with rows of teeth; two occipital condyles, their articu- 

 lar faces directed inward and backward; one pair of ossified 



" Cope, Proc. Amer. Phil. Soc, p. 187, 1877; Trans. Amer.Phil.Soc, 16, p. 287, 

 1886. Case, Jour. Geol. 8, p. 714, pi. II, ff. 12a, b, c; Bull. Amer. Museum Nat. 

 Hist., 24, 531; Revision of the Amphibia of the Permian of North America, 68, 

 141, 1911. Broili, Paleontographica, 51, p. 94, 1904; Anat. Anzeiger, 25, p. 586, 

 1904; ibid., 33, p. 291, 1908; Zittel, Grundzuge der Paleontologic, 2d ed., p. 218, 

 1911; Williston, Biological Bulletin, 15, 229, 1908; Jour. Geology, p. 600, 1910. 



