r 



( k 



r 



i 



rilK UArUACIIIA Ol' N'vtIiTII AMKIiU'A. 



99 



Ibriiiiidi ill the l»a.s(M)t tln' (tt()j;l<>.ssiil caitilajit'. Wlu'ro tlic latter is 

 lissuu'd tlm (!ivst appears to be deeurved tlir()ii.i>li it, as in C. inwoticus, 

 IM. i>5, Fiy;. (i. 



Tlie speeics of tiiis jfciius are distributed as follows: 



Al'sruoiMl'AKiAN lki',(ii()N. — ('. inivrn.sti)ni KK and (J. ritujulatus. 



Pacikk! liiiiaoN. — a. iKirotiouH, C.deoorticatiis, C. ittvrriinus, and C 

 tenchrosus. 



The (J. microstoinits is not coimnon in tlie eastern part of the Aus- 

 tioriparian re<:;i()ii, but is cliielly found in the Mississippi Valley and 

 Tt'xas. The Pacilic species are all northern, none beiiij; yet known 

 from the middle and southern [Kirts of California. 



The speeies of Vltondrotus are eliai'aeterized as follows: 



1. V()iiicr(>|iiiliitiiit', lootli scries cxtciulinj; fxtci-ior to (lit^ liiii! dC Ilm iiitcriiiil iiarcs; 

 liiiif|i;il plicir riidiatiii;; iVoiii iK^iiiul ; piirotoiils nut ilistiiict. 

 CI. Canlliim rostralisdistiiicl ; fail .sliorti'i- tliaii head and body. 



Miiz/.1(! i'lini;:ati', Hat, iii't«liiccd lii-voiid nostrils; voint'ioiialat iiir toctli in 

 two latlicr short scrii's, wliicli prcsi'iit an open an;;l(' backwards; brown, 



marl (led with darlicr brown spots f '. tviuhrosua, 



IF. Series of (ccth f\ti'ndMn;to external tissnre of innernares; liiif;iial plica' radiat- 



inj? from Ixdiind ; parotoid j^lands forming a distinct ovoid mass. 



ex. Teeth in thr(!(^ series (no canthiis roslralis o'- plantar tnbcrch.'s) ; fourth too 



with three phalanjj;es. 



Mnz/le not i)rodncc<l ; median series of teeth forniin}? an open anglo forwards; 



wi<ltli of head l") to j;roin ; legs stout; toes long ; tail longer than body ; 



nniforn: brown C. jHtrotieim, 



III. Series of teeth not extendin;. beyond inner lino of nares; lingual plica' radiat- 

 ing from behind ; no distinct parotoid mass (species large). 

 «. TwolviM'ostal folds ; no plantar tubercles; fourth toe with three j>lialanges. 

 Vomerine teeth in one transverse series behind i)osterii)r lino of choana' ; tail 

 nearly as long as head and liody ; inn/.zh! very obtuse ; nostrils terminal ; 



light brown, with ret iculations of dark brown C. dvanlictilK.'i. 



\'onierino teeth in t wo sigmoids, which converge and Join antorlorto elioana' ; 

 tail only as long as Imdy ; mu/.zle llat , produced beyond nostrils; unifortii 



black ('. (itcrrhnitii. 



(ill. Konrleen costal lolds; fourth toe with foui' phalanges. 



Teetl* arched between inner narcs; head one-fourth to groin (in small sptici- 

 mens") ; ey(M)nr-half width bet ween canthus; mn/zh" br()at; outer nearer 

 together than inner nares; brown, with a series of lighter sjnits on upper 

 part of sides, below yellowish; ninzzli' and tail marbled with the same. 



('. texaiiiiH, 

 \\. Series '>f teeth not ext<Miding Ik^voimI inner margin of nares; lingual i)lica' radi- 

 ating from a niiMlian longitudinal furrow of tin; tongue ; no distinct paro- 

 toid nniss (sjiecies small). 

 a. Two sci-ies of teeth; no canthus rostralis (fourth toe with four phalangoH). 

 ,<. Tail comiires.sed, eijual to tlm body. 



Ma-,idibh< shorter than muzzle; head elongate, width betwtu'u ^^yes behind 

 eiimil from sanui to narcs; width of head (i.o times in b iiglh to groin ; 

 limbs longer, .separated when a)ipress<'d, by t wo intercostal spaces ; black, 



wi 



111 numerous narrow gray aniiuli on bodv and tail. 



.(.'. ciiiuiilutiin. 



Mandible longer than miiz/le; head short, broad ; width between eyes behind 

 e(iiia\ from same to end muzzle; body stouter; width of head tJ.r) to 7 

 limes in length to groin ; limbsshort, separated by six costal spaces; lead- 

 colored, witli a few grav shades below (\ niicrostomm. 



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