'd. I'ro- 

 ill liirvic 



4 



THK nATKACIIlA OF NORTH AMERICA. 33 



''■"^I'l'''"'' rc«Iiici'(l ill si/c. In some fiuiiilii's the ptcryfj^oids iiover ossil'v, iiiitl (lis- 



••" !•• t''^' apitoiir. All illiistiation of the late persistence of the osseous ptei'yjjo 



• There palatine arch is seen in the larva of Cliondrotus IcnfbronUN. (See Plate 



21.) 

 l>ut soon 'j'lie tiyntcmatic urmixjemcnt of the Urodela may be represented us 



Dl.served follows: 



1. Iviili'ial jiiid iiicdiaii li.yoid ck-iiiciis (li.stiiiet. 



A. 'I'wo imirsdl' ciMJitoljriincl'.al Ixmcs; Htiipiis coimcctod with <|iiudi'titc arcli ; 



tiysell in no (lnnldc liyp()iio|di.vs('n. 'rrcmaloiUra. 



; and re- No lirst cpiliraiicliial ; no dimldt! lij i)oii()i)li\is('.s of vfrtidiiM' ; vrrtclna' aiii- 



SSer and jiliicirloiis; (■(.■riitdliyal comieutcd witli (|iiadrutt! by li^ainciil oiily; 



^ ^ ^ 1 voiiici()]>alat iiu! l)oiH'H witli teeth on tlie anterior margin; vcslilnihs 



witli nicnihranotis inner wall ; no iiaraHplienoid teetli. 



1 «l'<:'>"«') Cruiilohniiichiiln: 



'th, 3 be- ]{. One iiiiirolceratohrancliial bones; .stapeHconnccted \vitli<inadrate iircli; liypo 



ill iiiun liophysc's (h)uble. Aiiijiliinmoidai. 



'itions of No tiral epibranehial, several otiicr.s jircsent ; vertebra' aniidii(.(Ldoii.s ; an elli- 



• . ^1 ■ moid; scapular an<l pelvie arelies present; (•I'i'atoiiyai eoniieeled witli 



^ (inadrato by lifi;anient only ; liver little Hiib divided Iniphiiimidw. 



'^ C. Two pairs of eeratobraneliials; wtapes not conneeted with (luadrato arch in 



been de- ailult; only tlio lirsl and rarely second ei)ibraneliials iirrsent; verlc- 



iive been '"'"' without double hypoi)opliyses. I'ttriidosaiiria. 



»l\' biftir- ^" ^ L'lebra' aniphieielous. 



," ,. ,. VoMieropalatine bones with teeth on the iiosttirior niarjiin; eeratolival 



)lltttOIIOl ri J ,' 



connected with (inadrate by cartila^;e; no ])arasplienoid teetli ; vesii- 

 l^lts nave Ij,,!^ with osseous walls; carpus and tarsus ossiliiid; an otoyiossal 



allele of eartila^io ; no second epibranchial ideiiient Imbli/nlomidti: 



(1 i)V the Vouieropala-tine bones with teeth on tlie posterior iiiarj;in ; no itaiasjdie- 



noid tetJtli; no otoj^Iossal cartilage; a second c]iibranehial. 



(1,1,, Uijnohiidiv 



^ Vonieropalatinc bones with teeth on the posterior inarj;ins ; pariisplienoid 



I' siiiiple teeth; vestibule with osseous walls; ceratohyal eonueeted wilh 



raiichiais (piadrate by eartilaj^e ; no ototjlossal cartiiaj^e ; no second epibranch- 



|(, ccrato '"'; carpusand tarsuscartihif^iuous; no pteryjjoid I'hthodontiUv- 



■ ^,,^\^>^\^^■ 2. Vertebr.e opisthoc(elous. 



. Voinero|iaIatinc bones not sendinf^ processes over paraspheiioid bone; 



\ ceratohyal eonnccteri with (piadrate by cartilajre; paraspheiioid 



^'" "' 'he teeth; no ])()stfrontos(|uani()sal arch; carpus and tarsus cartila;;i- 



f lis si(l(-, nous iJcsmoyiiulhidtr. 



l>l;l(,. js, Voineropalatino bones not produced posteriorly ; paraspheiioid teeth; no 



j( j . ,,,,i> liostfroiitosi|uaiuosal arch ; carjiiis and tarsus osseous Thoriidw. 



\ tiueropalatine bones extended over parasplieiioids in two dontii;erous 



processes; no paraspheiioid teeth; no osseous postfrontosqiiatiiosMl 



Towards arch; ccrat(diyal only connected with quadrate by linanieut , carpus 



[)tcr,V.i;(»id and tarsus osseous Salumuiidrida: 



Wav from N'oincropalatinc bones extended over parasi)lieii(»id in two dentij;erous 



are much processes; no itaras|dicii{)id teeth; an osseous postfroiitos(|uainosai 



1 '. arch; ceratohyal only coiiiiccte<t willKiuadrate by lii^'anient ; carpus 



and tarsus osseous riviirodclido'. 



II. Tlyoid cleincnts continuous across middle line. No distinct median (dements, 

 .Stapes connected with (|uadral(^ hone. Aptidd. 

 » Vertehne with ihmblc hypojiophyses ; an ethmoid bone ^ scapular and pelvic 



II. ti7. •'"' arches wantiii",' ; liver greatly subdivided Caciliida: 



are derived 1U51— iJuU 3i 3 



MB 



