204 [December, 



upper jaw, immediately below the nostril, on each side of the head, is a curved 

 and perforated immovable fang about three lines in length ; there is no pit be- 

 tween the eye and the nostril, and this space is not channelled as in L. gracilis 

 and Kirtlandii ; several of the anterior teeth in the lower jaw are much larger 

 than the others ; the longest is slender and deeply fissured anteriorly. The neck 

 is contracted, the body long, thicker about the middle, covered above with long 

 and smooth quadrangular scales, arranged in thirteen rows ; the scales nearest 

 the abdomen are shorter than the others ; the tail is quite long, covered above 

 with four rows of short hexagonal scales, with margins more or less rounded 

 posteriorly ; the plates upon the under part of the tail are bifid. 



Color. Head olive colored above, lighter upon the sides ; the posterior margins 

 of the labial plates black; posterior margin of inferior labials also black; neck, 

 upper part and side of body green, the scales upon the posterior part of the 

 body bordered with black ; abdomen greenish, without spots or blotches ; tail 

 greenish olive, many of the scales bordered with black. 



Dimensions. Length of head 1 inch 4 lines ; greatest breadth 9 lines ; length 

 of the body 3 ft. 11 inch. 2\ lines; length of tail 1 ft. 5 inch. *l lines; total 

 lenth 5 ft. 7 inch. 2 lines ; greatest circumference 2 inch. 8 lines. 



I have named this serpent after my friend Ogden Hammond, Esq., of Charles- 

 ton, S. Carolina. 



Dimensions of a larger specimen. Length of head 1 inch 6 lines ; greatest 

 breadth 11 lines; breadth between the orbits posteriorly 9 lines; length of 

 body 4 ft. 62^ inches ; of tail 1 ft. 5 inch. 9 lines ; total length 6 ft. 1 in. 9^ lines ; 

 greatest circumference 3 inches. Abdom. scuta 225; 112 pairs of subcaudal 

 plates. 



Habitat. Liberia, W. Africa : Two specimens in the Museum of the Academy, 

 presented by Dr. Goheen. 



Remarks. The dentition of this animal is very remarkable, no serpent with 

 which I am acquainted having a single immovable perforated fang on each side 

 of the anterior portion of the upper jaw. It is well known to Herpetologists 

 that, although in Vipera, Naja, and other genera of venomous snakes, the exte- 

 rior row of teeth is wanting ; the poisonous fangs in certain serpents have behind 

 them a number of smaller grooved teeth. This condition exists, according to 

 Prof. Owen, in all the family of marine serpents, four such being found in Hy- 

 drophis striata, and five in Hydrophis schistosa. This is the case also in Bun- 

 garus, a land serpent, and in Hamadryas, a genus of poisonous tree snakes* in 

 India, established by Dr. Cantor.f In our own venomous serpents, Elaps, Tri- 

 gonocephalus and Crotalus, the exterior row of teeth is wanting. In this re- 

 spect they resemble Dinophis, but the fang in the latter genus is, as above 

 stated, quite immovable. In one of the specimens a movable perforated fang 

 was observed on the right side behind the other immovable one. 



Dr. Edward Whitaker Gray, in the Philosophical Transactions of London for 

 1789, makes some interesting observations on the *' class of animals called by 

 Linnaeus, amphibia ; particularly on the means of distinguishing those serpents 

 Avhich are venomous from those which are not so." He arrives at the conclusion 

 that the only mode of distinguishing a venomous from a non-venomous serpent 

 is by an examination of their teeth ; the tail, which is usually short in the 

 venomous species, being sometimes short in the innocuous. This is the case 

 in Pityophis affinis, and melanoleucus, both harmless serpents, with very 

 short tails. Serpents whose appearance indicates inoffensiveness are not unfre- 

 quently very dangerous, as in the instance above cited, and in that of the genus 

 Sepedon of Merrem, and Distichurus maculatus, which is quite small, and resem- 

 bles in its general appearance an ordinary Coluber, but is provided with a small 

 isolated fang on each side of the upper jaw. One of these, I have been informed, 



* These poisonous tree snakes are probably more numerous in the East than 

 is generally supposed. Dr. Ruschenberger informs me that in Siam he observed 

 a large green tree snake, which was said by the natives to be very venomous. 



t Proceedings of the Zoological Society of London, 1838, p. 72. 



