40 



iirij.KTiN :;i, r.Niri:!' si.\ri;s national mi;skum. 



li 



TIh- i'li;inictrr.s wliicli icstiiH Hit' li""''l.v '"■«' "'^ i<»Il"«'<: 



Nnclhmoi.l I'.ilatiiicl.oiM'siH.l piolon-oil over piinispliciioids, In-ar- 

 ,„;,. ,,,.,1, „i. the'ir postiTior iii:ii-iiis. Orhitosplieiioi.! scpiirati-d IVoiii 

 p,oMiirl.vii).'i,ihi;n,uiis\v:ills. liiU-niiil wall of vt'sliluih' osseous, (lar- 

 ,,„s iii.l" t usiis i.ssili,'(l. Vcrlchra", aiiii.Inco'Ious. I'refroiitals and 

 ,,t,.n....i.ls pivsciit. I'lciiiaxiUani's I'liUy (h-vclopo.l. I'arasplicnoi.l 

 witluMit dciiti-i'n.iis plates. An otojilossal caitila-v; only oiio, tlic lirst 

 (•piliiMMcliial ; srcoiiit hasiltiaiicliial i:<i)lati'd. 



We may lu'ic obsoive the si-nilieaiice ol" the fVatuies doliniiif;- this 

 laiiiily. Twoof tliec,liara('tersassi;,nied an> what I have termed nioi'idiie; 

 that is, one lias not Ix'cii assnined after iiossession of the other, nor is 

 it identical with the ininiatnre sta.ye of the same. Such are the short- 

 ened form of the i»alatine bones, as coniitared with the posteriorly i)ro- 

 (hiecd lamina' of tin' Salamaudrida-. and the absence of deiitij?eious 

 plates on the paras]ilieiini(l in the IMetlKMlontida' is a character of the 

 same kind. Under sneh eirciunstanees we infer tliat the fanulies ex- 

 liiliit an ontojieny moditied by eienoj-eny. 



The biconcave vertebra- constitute a ix-rsistence of a larval feature. 



The preseuce of ptery.i;oids has the same siynilicancc with refereuce 

 toother families. 



Theossilieatiou of the carpus and tarsus are characters in which this 

 •iKiiip develo])s beyond the larval condition which is permanent in the 

 family riethodontiihe. 



Thus of eight characters fAo are iiKuphic and six developmental; 

 of the six, two are of advanced develoi»inent and four of reitrcssed 

 development, as compared with other fanulies. 



The writer characterized this family nearly as above in the .lourual of 

 the lMiiladelj)hia Academy, lS(i(!, 105. J)r. Ilallowell proposed it in the 

 same worii, 1858, 337, but on iiisulllcient characters. iMany of the char- 

 acters of the i)riiicii)al {^enus Amblystoma had been already pointed 

 out by Professor ilaird. The .yenera imduded by Ilallowell were Am- 

 blystoma, Xijiltonura Tsch , and Onychodactylus Tschudi. Clray had 

 previously end)raced the same genera with llctvrotriton dray, in liis 

 first section of the IMethodontida', which corresponds with this family. 

 The writer in lS5',)embraeid Onychodactylus, Amblystoma, Camarata.iis 

 Cope, and 3Ie,ualol)atrachus Tschudi. in the above citetl essay of 1S(»<» 

 the {ieiiera are limited to the two first nuMitioned with Ihimtinn (Iray. 



The wivestijiation of the subject which I j^'ave in my nujuograph of this 

 family, i.ul)lislied in IS!);), n'sulted in the followinj,' disposition of these 

 supposed jiencra, 15;iiid having- already shown the identity of Xiphn 

 num with Amblystoma. ^^ llcfcrotriton is identical with Amblystoma. 

 Megalobatrachus, the great salamaiuler of Japan, I have determined 

 to pertain to the Cryptobranchida'. The genus Camamtaxh, as will 

 appear further on, was established on a larval character, permanent 

 in some individuals it is true, but not permanent in any si)ecies. On 

 the other hand, there is some probability that onci or both of the species 

 of riynobius Tschudi from Japan enter the landly, but this I am not 



