1872.] DR. A. GUNTHER ON TWO SPECIES OF HYDROSAURUS. 145 



4. On two Species of Hydrosaurus from the Philippine 

 Islands. By Dr. Albert Gunther, F.R.S., F.Z.S. 



[Eeceived January 26, 1872.] 

 (Plates VII. & VIII.) 



A distinct species of Hydrosaurus from Mindanado was de- 

 scribed as long ago as 1838, by W. Martin, in the 'Proceedings' of 

 this Society (p. 69), under the name of Varanus cumingii. This 

 extremely well characterized species has never since been recognized ; 

 and I felt much gratified when, on looking over the specimens of 

 this family in the British Museum, I discovered the typical specimen 

 sent by the late H. Cuming to the collection of the Zoological So- 

 ciety. It was obtained for the British Museum in 1857, and has 

 still the original labels attached to it : — one in Cuming's handwriting, 

 signifying the locality, " Isle of Mindanado ;" and the other written 

 hy Martin, with the date of reception into the Society's collection, 

 and the names of the sender and species. 



The description by Martin is so complete that I need not add 

 any thing else but a figure of the upper parts of the head and neck, 

 showing the unusually large plates on the crown of the head, by 

 which the species will be readily recognized. Also the scales of 

 the neck and along the middle of the back are conspicuously larger 

 than in Hydrosaurus salvator, convex, and ovate in shape (see 

 Plate VII.). 



In a collection from the Philippine Islands, recently presented hy 

 Harry J. Veitch, Esq., to the British Museum, there is a large Hy- 

 drosaurus which, although it resembles H. cumingii in having large 

 convex dorsal scales, differs in the pholidosis of the head, and is 

 distinguished from all its congeners by the extraordinary development 

 of the nuchal scales. It may be characterized thus : — 



Hydrosaurus nuchalis. (Plate VIII.) 



All the scutes on the upper surface of the head are of nearly uni- 

 form small size, with the exception of a series of enlarged transverse 

 scutes in the superciliary region ; a central scute in the middle of 

 the crown of the head is also larger than the others. The scales on 

 the neck are very large, larger than any of the scutes of the head, 

 flat, and somewhat distant from one another, smaller scales being 

 mixed with the large ones. The dorsal scales gradually diminish in 

 size in the middle and hind part of the length of the body, but are 

 throughout conspicuously larger than on the sides of the back. 

 Claws of moderate strength, the anterior stronger than the poste- 

 rior. Teeth strong, slightly compressed, curved backwards, and 

 finely serrated behind. Scales of the belly smooth, in eighty-three 

 transverse series between the gular fold and the loin. Upper parts 

 brownish black, with indistinct ovate yellowish spots arranged in 



Proc. Zool. Soc— 1872, No. X. 



