112. ATBACTTT8. 299 



2. Dirosema omiltemannm. 



Geophis omiltemnna, Giinth. Biol. C.-Am., Kept. p. 92, pi. xzxiii. 

 fig. A (is 



Snout broad, rounded. Rostral a little broader than deep, visible 

 from above ; internasals much broader than long, about two fifths 

 the length of the pnefrontals ; frontal broader than long, as long as 

 or slightly longer than its distance from the end of the snout, much 

 shorter than the parietals ; nostril between two rather large nasals ; 

 loreal at least twice as long as deep ; a small subocular may be 

 present between the loreal and the third and fourth labials ; two 

 postoculars; temporals 1 + 2; six upper labials, fourth or third and 

 fourth entering the eye, sixth very long ; two pairs of chin-shields, 

 the anterior a little the longer and in contact with four lower labials. 

 Scales in 17 rows, dorsals faintly keeled. Ventrals 150-166 ; anal 

 entire ; subcaudals 38-51. Black, with whitish cross bars widening 

 towards the belly, which is white ; these bars less distinct and 

 closer together on the posterior part of the body ; upper lip white ; 

 subcaudals brown or speckled with brown. 



Total length 305 millim. ; tail 65. 



Mexico. 



a-c. <S (V. 150; C. 61) & OmUteme, Guerrero. Mr. H.H. Smith [C.]; 

 hgr. ( V. 166, 166 ; C. 38, F. D. Godman, 



60). Esq. [P.]. (Types.) 



3. Dirosema psephotnm. 



Catostoma psephotum, Cope, Jotirn. Ac. Philad. (2) viii. 1876, p. 146. 

 Elapoidis psephotus, Cope,Proc. Amer. Philos. Soc. xxii. 1885, p. 386. 

 Geophis psephota, Giinth. Biol. C.-Am., Kept. p. 94 (1893). 



Nasal undivided; two postoculars; temporals 1 + 2; six upper 

 labials, third and fourth entering the eye, sixth longest ; two pairs 

 of chin-shields, posterior short. Scales keeled, in 1 7 rows. Ventrals 

 162; anal divided ; subcaudals 73. Above uniform black; below 

 black with the half or less of an occasional ventral shield red, 

 forming a tessellated pattern. 



Total length 480 millim. ; tail 128. 



Costa Rica. 



4. Dirosema brachycephalum. 



Colobognathus brachycephalus, Cope, Proc. Ac. Philad. 1871, p. 211. 

 Catostoma brachycephalum, Cope, Jotirn. Ac. Philml. (-2) viii. 1876, 



p. 147. 

 Elapoidis brachycephalus, Cope, Bull. U.S. Nat. Mus. no. 32, 1887, 



p. 86. 



One postocular ; six upper labials, third and fourth entering the 

 < ye, fifth in contact with the parietal. Scales in 15 rows, with a 

 faint trace of carination near the posterior part of the body. 

 Ventrals 124; anal entire; subcaudals 38. Black above, with a 

 yellowish collar and a yellowish lateral streak ; vcntrals reddish, 

 brown-margined. 



Total length 200 millim. 

 Costa Rica. 



