CROCODILIANS, LIZARDS, AND SNAKES. 



1011 



TROPIDOCLONIUM Cope. 



Tropidoclonium Copk, Proo. Acad. Nat. Sci. Phila., 1860, p. 76; Proc. Anier. Phil. 

 Soc, 188G, p. 495; Bull. IT. S. Nat. Mns., No. .32, 1887, p. 60. 



Head not distinct from body. Teeth equal. Scales keeled; anal 

 plate entire; subciiudal scuta divided. Cephalic scuta normal; two 

 iiiteniasals, rostral not prominent. One nasal and one loreal. 

 Hemip.enis with two apical papilla". 



This genus shows its position to be in the Natricina^ by the presence 

 of the vertebral hypapophyses on the posterior part of the column. 

 In its entire anal i)late, and in its pattern of coloration, it resembles 

 the genus J^Jntcvnia, and especial!}' such species as IJ. hrachysionia Cope 

 and E. leptocephala Baird and Girard, where the head is not very dis- 

 tinct. It is probably a terrestrial modification of that genus, as the 

 Natri.r /cirtlandii is oi Xatrix. But one species of the genus is known. 

 The peculiar apical papilhc of the hemipenis I find to be entirely 

 constant. 



TROPIDOCLONIUM LINEATUM Hallowell. 



Tropidoclonium lineatum Copk, Proc. Acad. Nat. Sci. Pliila., 1860, j). 76; Check- 

 list N. Amer. Batr. Kept., 1875. p. 42. 

 Micropa lineatus Hallowkll, Proc. Acad. Nat. Sci. Phila., 1856, p. 241. 

 Ischnognathuft lineatus Bouienger, Cat. Snates Brit. Miis., I, 1893, p. 289. 



The head is quite sma^.l, rounded above, depressed in front; snout 

 subacute; nostril in a single parallelogrammic nasal plate, quite near 

 its superior margin, and 

 much nearer its anterior 

 than its j)osterior ex- 

 tremity; sometimes this 

 plate is cleft inferiorly 

 below the nostril; loreal 

 longer than high; one 

 anterior, two posterior 

 orbitals; six superior la- 

 bials, the eye resting on 

 the third and fourth, the 

 sixth longer than high. 

 Temporals 2-2, the infe- 

 rior of the first row not 

 touching postorbitals, 

 and intercalated between 

 the fifth and seventh 



superior labials. Pregeneials longer than postgeneials, the latter 

 bounding the x»osterior part of the long fourth inferior labial. Body 

 rather stout, thicker in the middle, covered with nineteen rows of 

 scales, all of which are very strongly carinated, except the two inferior 

 rows, which are quite smooth and deeper than the others; other scales 

 narrow, subelliptical, bipuuctate posteriorly, the carina reaching the 



Fig. 2TA. 



Tropidocloniim line.\tum IIali.owell. 



X 2. 



Fort Cbadboiirne, Texas. 



Cat. No. S05», U.S.N. M. 



