24. TRACHISCHIUM. 
2. Hydrablabes preefrontalis. 
Ablabes periops, var. preefrontalis, Mocquard, Le Natur. 1890, p. 154, 
ind ee Ah us. (8) i 1000, 187, pli ix. J : 
rontalis, Bouleng. Ann. . N. HH. (6) vii. 
891, ai : x / 
Distinguished from the preceding by the fusion of the prefrontals 
into a single shield, and 15 rows of scales. Ventrals 178-180. 
Olive-brown above, with two pairs of blackish longitudinal streaks. 
Kina Baloo, North Borneo. 
24. TRACHISCHIUM. 
Trachischium, Giinth. Cat. Col. Sn. p. 30 (1858); Bouleng. Faun, 
 Ind., Rept. p. 284 (1890). 
Ablabes, part., Giinth. Rept. Brit. Ind. p. 223 (1864). 
Maxillary teeth 18 to 20, subequal ; posterior mandibular teeth 
shorter than the anterior. Head not distinct from neck ; eye small, 
E with vertically subelliptic pupil ; nostril between two small nasals ; 
az prefrontals sometimes united. Body cylindrical ; scales smooth, in 
13 or 15 rows, without apical pits; ventrals rounded. Tail short ; 
‘ subcandals in two rows. Hypapophyses developed throughout the 
vertebral column. 
- Eastern Himalayas and Khasi Hills. 
4 Synopsis of the Species. 
I. Scales in 13 rows, those of the ischiadic region keeled in the 
males. 
Prefrontal shield usually undivided; one 
postocular; 150 ventrals or more...... 1. fuseum, p. 297. 
Prefrontal shield usually undivided; one ; 
' postocular; 132-145 ventrals ........ 2. gquentheri, p. 298. 
Two prefrontals ; two postoculars ...... 3. tenuiceps, p. 299. 
II. Scales in 15 rows, all smooth. 
Sixth upper labial largest ........ ancahs 4. monticola, p. 299. 
Last three upper labials subequal........ 5. rubriventer, p. 300. 
1. Trachischium fuscum. 
Calamaria fusca, Blyth, Journ. As. Soc. Beng. xxiii. 1854, p. 288. 
—— obscuro-striata, Blyth, 1. c. 
Trachischium rugosum, Giinth. Cat. p. 30 (1858). 
—— fuscum, Giinth. Proc. Zool. Soc, 1860, p. 161; Theob. Cat. t. 
As. Soc. Mus. 1868, p. 45; Anders. Proc. Zool. Soc. 1871, p. 171; 
Theob, Cat. Rept. Brit. Ind. p. 144 (1876); Bouleng. Faun. Ind., 
. p. 285 (1890). 
Ablebee fuscws Giinth. Rept. Brit. Ind, p. 225 (1864). 
Rostral as broad as deep or a little deeper than broad, visible 
