90 OPHIDIA. 
the occipital. The first pair of lower labials do not meet in the median line of the 
chin. Seventeen series of scales, those in the lumbar region keeled (apparently, some- 
times all smooth). Ventral scutes 146. Above uniform dark coloured, below whitish. 
If I am correct in supposing that Bocourt’s Geophis dubius is distinct from the 
species described by Peters under that name, then it is very probable that the former is 
specifically identical with Jan’s Geophis rostralis, this species being subject to variations 
similar to those of Geophis chalybea. 
4, Geophis semidoliata. 
Rhabdosoma semidoliatum, Dum. & Bibr. Erpét. vii. p. 93; Giinth. Col Sn. p. 10; Cope, Bull. U.S. 
Nat. Mus. no. 82, p. 85. 
Catostoma semidoliatum, Cope, Proc. Ac. N. Sc. Phil. 1861 (1860), p. 339. 
Elapoides semidoliatus, Jan, Iconogr. Ophid. xii. t. 2. fig. 1. 
Geophis semidoliatus, Peters, MB. Ak. Wiss. Berl. 1859, p. 276; Bocourt, Miss. Sc. Mex., Rept. 
p. 584, t. 31. figg. 7, 7a-c; Garman, Mem. Mus. Comp. Zool. viii. no, 3, 1883, p. 102. 
Hab. Mexico, Jalapa and Orizaba (Brit. Mus.), Misantla and Zacualtipan (Cope), 
Huatusco (Godman). 
A supraocular and one postocular, sometimes confluent into one scute. ‘Two pairs 
of frontals and two pairs of chin-shields. Five upper labials, the third entering the 
orbit. Fifteen series of smooth scales; anal entire. Yellowish, orange-coloured on 
the back, with broad black cross-bands, rather irregular in shape. 
This species seems to be extremely common at Jalapa. 
5. Geophis mesta. (Tab. X XXIII. fig. C.) 
Geophis mestus, Giinth. Ann. & Mag. N. H. 1872, ix. p. 15. 
Hab. Mexico, Amula (H. H. Smith); Costa Rica, Cartago (Mus. Brit.). 
Head rather broad, short and depressed; body and tail of moderate length. Eye 
small, with the pupil elliptical. Anterior frontals well developed, about one-eighth 
the size of posterior. Vertical as broad as long, six-sided, with the anterior angle 
rather obtuse, and with the posterior somewhat pointed; its lateral edges are very 
short, convergent. Supraocular well developed. Occipitals rounded behind, shorter 
than the vertical and postfrontals together. Six upper labials, the third and fourth 
entering the orbit; the fifth is the largest, and forms a suture with the occipital; an 
elongate temporal behind this suture. One postocular. The first pair of lower labials 
form a suture together; anterior chin-shields of moderate extent. Scales in fifteen 
rows, mostly smooth, but those in the dorsal region above the vent keeled. Ventrals 
140-148; anal entire; subcaudals 41. Coloration entirely black, with a broad white 
collar, occupying a portion of the occipitals and the temple. Lower parts blackish 
or whitish. 
