OCR Text |
Show 1871.] DR. J. ANDERSON ON INDIAN REPTILES. 195 twenty-three rows. Two specimens before me have twenty-four rows of keeled scales, two others have twenty-five, and three others have twenty-three. One of the specimens with twenty-three is from Darjeeling ; and the two others are from Cheera Punji, Khasi Hills. In the specimens from the latter locality one has a pair of small shields between the supranasals, and another has three small shields intervening between them. Another specimen from Darjeeling, with twenty-five rows of scales, and measuring 28 inches 6 lines, tail 3 inches 2 lines, has a pair of shields between the supranasals, and three small shields in front of the former, evidently resulting from division of the supranasals themselves, and of the azygos also. It is a female, with ventrals 146, caudals 35. The coloration is in every way the same as described by Gunther. I observe in Giinther's figure of this Snake that a small azygos shield is impacted between the supranasals and rostral; and if this shield were a little enlarged, and were completely to separate the supranasals, his figure would agree in every respect with m y seven specimens from Darjeeling, all of which have an azygos shield between the supranasals, and from twenty-three to twenty-five rows of keeled scales. The occurrence of twenty-four rows in two of the specimens leads to the apparent limit of variation, twenty-five. It is easy to understand how the azygos may become broken up. The coloration of all these specimens (twelve), including T. andersoni, is identical in every respect; and, as Gunther observes, the males are blackish ash, and the females and young pale brown. The aged females, however, become dark brown. The Y-marking on the neck is present in all. The adults measure 4" 9'" in circumference. The smallest specimen measures 6" 9"', of which the tail is 1"; and the largest 32" 3"', tail 4" 10'". The ventrals vary from 140 to 148, caudals from 36 to 48. Hab. Darjeeling ; Cheera Punji, Khasi Hills ; Hotha, Yunan, N . China, 3520 to 5000 feet. With these facts before us, the scales may be said to vary from twenty-three to twenty-five rows; and the supranasals m a y be regarded as varying from a minute shield impacted in front of them, to a perfect shield, wholly separating them, or breaking up in some cases into two or five supranasal shields. These differences m ay be regarded as indicating special varieties ; but it is very questionable whether they are invariably communicated from the parent to its offspring. I a m inclined to think they are not, for I have on more than one occasion, when examining young Snakes that I have removed with m y own hands from the mother, found them exhibiting variatious in their head-shields; and the occurrence at Darjeeling of specimens of this Snake with twenty-three rows of scales, while the majority have twenty-five rows, is conclusive proof that this character is not one characteristic of a local form. It is curious to remark that all the specimens that have hitherto yielded twenty-three rows of scales have not been adults, and that all m y largest specimens yield the greatest number of scales round the neck; and in the light of such a consideration it seems possible that mature forms from Cheera Punji will yield twenty-five rows of scales. |