iiEUPirruLOay. 317 



P. scuTATUs, Laur. 



Sciilus on neck, in 21 to 23 rows. An azyf!;os shield hctwcen the posterior 

 frontals. Crown of the head hlack. Body siurouuded by 2.5 to .00 black rings. 

 Grows to 5 feet. 



Bay of Bengal and Eastern seas. 



P. FiscnuKi, Jan. 



Scales on neck, in 19 rows. N'o azygos sliiuhl b<'t\veen the posterior frontals. 

 Body surrounded by 3;i to 36 black rings. A black baud across the occiput and 

 vertical, extending to the lower jaw. Snout yellow. Lower labials black. Length 

 30 inches. 



Bay of Bengal and Eastern seas. 



P. Ai'i'i.Nis, Anderson. 



Resembles P. Fisrheri in having 10 rows of scales, no azygos shield, and other 

 details. It resembles J', sciitdtas iu having iJG black rings and the head wholly black. 

 Length 49 inches. 



Tolly's Xullah, Cahnitta. 



Till "more specimens are procured, there seems some doubt if there arc three 

 species, or only one rather variable one, of this genus. 



HYDKornis. 



Head shielded above. One pair of frontals. Nostrils superior in a single shield. 

 Ventral sliields narrow, rudimentary or absent. 



A. Scales imbricate, 

 a. Scales in not more tlian 17 nnrs round the neck. 

 H. jKiuxi-Nir, Gray. 



h. Scales in 38 fo 13 roics round the ncclc. 



H. GKANOSA, Anderson. 



Habit moderately slender. Scales in 43 rows round the neck. Keels slightly 

 dilated at either extremity. One praaocular, one postocular. The ventrals arc twice 

 the size of the adjoining scales, and carry cither 2 or 4 tubercles. Six anal shields, 

 the outer very large. 52 non-confluent bhu k bands down the body. 



This species is nearest to II. Stvkesii, which it may represent in the Eastern seas. 



H. TUBEECULATA, Andcrsou. 



Scales in 38 rows on the neck, longitudinally bitubercular. One prajoeular, two 

 postoeulars. The fourth and fifth labials below the eye. Scales of the liead pro- 

 fusely granulated. Two pairs of large chin shields. Ventrals 321, about twice 

 the size of the adjoining scales, irregular, anteriorly largest, each ventral minutely 

 tubercled at the sides. Four anal shields, the external largest. Body encircled by 

 59 black bands and the tail by 8, broadest above. Colour above olive yellow, below 

 bright yellow. A dark patch on the crown. A yellow hand between the orbits, 

 continued to the neck. A dark streak down the yellow upper labials. 



Length 49 inches. 



Differs from its nearest ally, II. granosa, by its reduced number of scales, two 

 postoeulars, chin shields, etc. 



Tidal branches of the Hugli. 



c. Scales in 23 to 38 rows round the ncch. Head not very small. 

 Keck moderately or not slender. 

 * One postocular. 

 H. MAJOR, Shaw. 

 Belly with only a few ventral shields. Scales keeled, 31 rows on neck. Four 



