140 
ON THE PHYSIOGNOMY OF SERPENTS. 
posed in 15 rows, and its body is more elongated. S'. 
190 + 64. Extremely rare. 
3. Heterodon coccineus, the third and last species of 
this genus, is of smaller size, has a pointed head, a pro- 
jecting but not turned-up snout, and the body is of a 
burning-yellow, marked by broad spots of a purplish-red. 
B. S. 19. S. 170 + 50. This species comes from Mexico 
and the southern provinces of the United States. 
L Y c 0 D 0 N. 
The Lycodons compose the fourth genus of non-venom- 
ous Terrestrial Serpents. They are Ophidians of a middle 
size, with a body usually slender, and sometimes thread- 
like. Their characteristic is the possession of anterior 
maxillary teeth longer than the rest. Their eyes are small, 
the pupil vertically elongated. The vertical plate, and the 
anterior frontals,are small and aggregated, but the oecipitals 
are considerably elongated ; there is only a single frenal. 
The scales are lozenge-shaped, and usually smooth ; the 
abdomen is angular in most of the species, and the tail is 
often defended by simple scuta. The dominant tint is an 
earth-brown ; the scales are sometimes bordered with 
white, and the neck ornamented with a bright collar; 
other species have the body annulated with black, white, 
or red. The Lycodons inhabit the equatorial regions of 
both worlds, but they are unknown in New Holland. 
1. Lycodon Hebe, the first species, has a depressed 
head, and obtuse muzzle. The posterior frontal plates and 
the oecipitals are very long. Bows of scales, 17* S. 
196 -f- 68. Colour, a brown-grey, more or less dark above, 
ornamented with bright and chequered spots. This last 
tint borders the scales, and forms a broad collar. The 
distribution of the colours is subject to accidental varieties ; 
others arise from climate ; the specimens from Bengal are 
very bright ; those from Java and Timor are deeper, and 
of a less robust make. 
2. Lycodon carinatus, a native of Ceylon, where it is 
very rare. It has simple scuta under the tail, and the 
carinated scales are disposed in 17 rows. Colour, coffee- 
