112. ATBACTU8. 299 



2. Dirosema omiltemanum. 



Geophis omiltemana, Giinth. Biol. C.-Am., Rept. p. 92, pi. xxxiii. 

 %. A(180S). 



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

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

 the length of the prsefrontals ; 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 row^, dorsals faintly keeled. Ventrals 150-166 ; anal 

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

 towards the beUy, 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 miUim. ; tail 65. 



Mexico. 



a-o. S (V. 150; 0. 51) & Omilteme, Guerrero. Mr. H. PI. Smith [0.1; 

 hgr.(V. 166, 156; 0.38, F. D. Godman, 



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



3. Dirosema psephotum. 



Catoatoma psephotum. Cope, Journ. Ac. Philad. (2) viii. 1876, p. 146. 

 Elapoidis psephotus, Cope, Proc. Amer. Philos. Soc. xxii. 1885, p. 886. 

 Geophis psephota, Giinth. JBioL C.-Am., Rept. 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 17 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 milUm. ; tail 128. 



Costa Rica. 



4. Dirosema brachycephaliim. 



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

 Oatostoma brachycephalum, Cope, Journ. Ac. Philad. (2) viii. 1876, 



p. 147. 

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

 p. 85. 

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

 eye, 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 ; ventrals reddish, 

 brown-margined. 



Total length 200 millim. 

 Costa Rica. 



