in the Collection of the British Museum. 359 



Dipsas nigriceps. 



Scales in 21 series; head uniform blackish above. 



Body and tail very long and slender, much compressed ; head 

 broad and depressed ; eye large. Vertical shield large and 

 broad ; loreal as high as long ; one prseocular, in contact with 

 the vertical ; two postoculars. Eight upper labials, the third, 

 fourth, and fifth of which enter the orbit. Vertebral scales 

 large, six-sided. Temporals rather irregular, 2+2 + 3. Ven- 

 trals 263; anal entire; subcaudals 120. The two or three 

 anterior teeth on the palate somewhat larger than the others. 

 Light reddish olive, irregularly mottled with brown ; upper parts 

 of the head uniform blackish, the lower yellowish. 



Habitat ? 



Total length 65 inches ; tail 15| inches. 



Heterolepis, Smith, and Simocephalus, Gray. 



Sir Andrew Smith was the first who introduced these highly 

 interesting Snakes into science, in his magnificent work on the 

 * Zoology of South Afinca.' He was acquainted with two kinds : 

 one of them, discovered by himself in the Cape Colony, was named 

 and described by him as Heterolepis capensis ; the second, from 

 Fernando Po, was known to him from a specimen in the British 

 Museum, named by Dr. Gray Simocephalus poensis. Although 

 he did not give a detailed description of the latter, he charac- 

 terized it sufficiently/ well to ensure its identification by later 

 herpetologists, referring it to the same genus as the form dis- 

 covered by himself. Therefore it was perfectly superfluous on 

 the part of Dumeril and Bibron to introduce another name for 

 the second species, which had previously been given to it in a 

 manuscript or in a museum, but which could not have any claim 

 to recognition whatever, because it had never been published 

 with a proper diagnosis. 



When the ' Catalogue of Colubrine Snakes in the British 

 Museum ' was published, it appeared to me that the great dif- 

 ference in the form of the head between these two snakes would 

 be sufficient for their generic distinction, Heterolepis capensis 

 being distinguished by an ovoid head, with a truncated and 

 scarcely depressed snout, whilst the head of H. poensis is much 

 depressed, with the snout broad and spatulate. Therefore I 

 adopted for this second species a generic name proposed by 

 Dr. Gray, and characterized this genus Simocephalus. On re- 

 examination, I still adhere to this opinion, although I have not 

 had the opportunity of seeing the typical specimen of Hetero- 

 lepis capensis, which, I am sorry to hear, has gone, with many 

 other equally valuable typical specimens of the ' Hlustrations of 



