in the Collection of the British Museum. 29 



Lycophidium Horstockii. PI. VII. fig. A. 



I have mentioned, in 'Colubr. Snak.' p. 197, that large spe- 

 cimens about 2 feet long appear nearly uniformly black, a small 

 number of scales on the posterior part of the body retaining 

 bluish-white edges. 



We have received a very singular variety from the Gambia, 

 through the kindness of Sir Andrew Smith : one of the speci- 

 mens is 21 inches long, and the other about half that size. 

 This is black, nearly all the scales having bluish-white edges. 

 A series of thirty quadrangular white spots occupies the back of 

 the trunk, each spot enclosing nine or ten scales. The series 

 commences with a white longitudinal streak on the neck and 

 occiput, and terminates with about seven streak-like spots on the 

 back of the tail. 



This extraordinary variety might be taken as a distinct species; 

 but there is not the slightest structural diflference from the typical 

 L. Horstockii. 



Aspidiotes melanocephalus, KrefFt. 



Mr. Kreflft has kindly sent to the British Museum a fine large 

 specimen of this snake. I could not discover any teeth on the 

 maxillary bone ; so that Mr. Krefft appears to be justified at 

 present in placing this snake among the Boidce. However, 

 there is in other points such a strong similarity to Liasis, that 

 I cannot help thinking that an examination of younger examples 

 of 2 or 3 feet in length may reveal the presence of those teeth. 



Atractaspis microlepidota. PI. VII. fig. C. 



Uniform blackish brown. Body stout. Ventrals 212 ; sub- 

 caudals simple, 26. Scales in twenty-nine series. Two pairs 

 of frontal shields; one prse- and one postocular; six upper 

 labials, the third and fourth entering the orbit; temporals 

 rather numerous and irregular. 



This is probably a West African species. Our specimen is 

 20 inches long, the tail measuring 18 lines. 



Atractaspis corpulentus. 



According to Hallowell's notes (Proc. Acad. Nat. Sc. Philad. 

 1857, p. 70), his specimen had one pair of frontals and 182 

 ventral shields; our specimen differs in having two pairs of 

 frontals and 210 ventral shields. However, we have seen similar 

 variations in one and the same species of African snakes, and 

 would not regard the two specimens as specifically distinct, 

 without further proof. 



The British Museum now possesses four very distinct species 

 of this genus, so characteristic of the western and southern parts 

 of Africa. 



