228 Zoological Society ;— 



this region, that at present there is not one species known of the 

 genus Tropidonotus. Schlegel beheved he found its representative in 

 J)as}jpeltis scaler ; but a snake living on trees, devouring birds' eggs, 

 the shells of which it breaks by its gular teeth, with an irregular 

 arrangement of the lateral scales, is a form quite peculiar in itself, 

 and peculiar to this region. Highly interesting is the fact, that 

 more than one-third of the genera live on trees, which ratio is 

 never met with in any of the other regions : there we find a member 

 of the family oi Lycodontidce (a family which contains either Ground- 

 snakes, or forms only slightly approaching to that structure which 

 indicates the capability of climbing trees) entirely transformed into a 

 very Tree-snake {Simocephalus) . There we find Tree-snakes with 

 perforated fangs in front (Dendraspis) . The African species of Naja 

 (N. haje), so closely allied to the Indian Cobi-a de Capello, is to be 

 considered as a Tree-snake as well as Ground-snake, whilst N. tripu- 

 dians never appears to climb trees. But the Indian and the African 

 species offer a similar series of varieties ; and it would be, in many 

 cases, very difficult to assign one of those varieties, if of unknown 

 origin, to the right species, without the single character of the sixth 

 upper labial shield. The question whether those varieties really are 

 species is not yet decided. Every large collection should obtain as 

 many specimens as possible of both forms, with the most accurate 

 accounts of their localities. There are about 70 specimens in the 

 collection of the British Museum ; but even with this number I 

 was unable to distinguish separate species within accurately limited 

 boundaries. 



Another peculiarity of this region is the abundance of Snakes pro- 

 vided with longer front teeth, or Lycodontidce ; and it agrees also in 

 this respect with India : in fact, the western and middle Palaeotropical 

 regions equally partake of this family, each region producing a form 

 with entire subcaudal plates. Venomous Colubrina here form a great 

 portion among the Ophidia, a greater one than the true Viperina ; 

 and they also exhibit quite a peculiar group, namely such Colu- 

 brina as are provided with permanently erect and perforated fangs 

 {Dendraspis, Atractaspis). Our knowledge of the whole region is 

 very limited, as also is the case with the large island connected 

 with it, Madagascar. The following Snakes are known belonging to 

 its fauna : — 



Sanzinia. Pelophilus. 



Heterurus gaimardii and arctifasciatus. 



Psammophis sibilans, var. 



{Herpetodryas bernierii. Isle de France.) 



Herpetodryas quadrilineatus. 



Enicognathus rhodogaster. 



Vhilodryas miniatns and goudotii. 



AhcBtulla lateralis. Langaha. 



None of these Snakes, except Psam. sibilans, have been found on 



the continent of this region, or in any other part of the globe ; and 



it may be a question, as already suggested by Schlegel, whether such 



a separate and peculiar fauna as that of Madagascar might not furnish 



