ANATOMY OF CRYPTOBRANCHUS ALLE- 

 GHENIENSIS 



ALBERT M. REESE 

 The Skeleton 

 The Skull 



Since the skull of Crypfobranchiis allegheniensis is strong and" 

 largely composed of bone, it is easy to prepare and to study. Figs. 

 1 and 2, A and B, are dorsal and ventral views of the skull proper 

 and of the lower jaw, taken from photographs. 



The skull as a whole has essentially the same structure as that 

 of the Japanese giant salamander, described and fiL-'urcd hy 

 Osawa f:02), but it differs from the latter sonu u hat in -cncral 

 outline and in the shape of some of its constitncnl Ix.nc-. Its 

 length is greater in proportion to its width than h tlic cast^ with 

 the Japanese species, and the anterior outline ot the head, tornicd 

 by the maxillary and prcinaxillarv bones is more rounded m the 

 American species, in whieli it forms an almost ixM-lecl arc of a 

 circle. In the Japanese form the niaxilhe and preiiiaxilhe. as 

 figured by Osawa, are relatively heavier tlian m the Amenean 

 species, and the posterior ends of tlie nuiMHarv l.one^ approach 



of the lower jaw i-> about the Mm( m Ixlth -[..(u^ Lur it no- 

 thing, is mirn.wer in tlu Vnuiuan Mlimiii.lu m. tint it .Iocs 

 not ht with ^u^ U i.M<i>ion a, ni.st th. uppu | iw I he 

 anteiior boidei of the ^kull i. tomud a^ ha^ luui ^ai.! U^ the 

 maxillary and premaxillarv bones il-ius. 1.2..;. M.r.. .l/.r.\ l)otli 

 of which are armed with niimeroii> >ma!l. conica! teeth, tlierc 

 being about 12 on each prema\illa and on eacli niaxiUa. making 

 100 teeth in the entire row. 



The cartilaginous portions ot tlie skull are not so e.\tenM\c as 

 in the Japanese salamamh'r. and are snperfieiaiiv ve^ilih- m the 

 region of the anterior nans onlv. the ani.'rior [)art ot the orhit. 



