JAVA. 23 



record is based on an example in the Senckenburg museum at Frankfurt on the 

 Main. Werner (Zool. jahrb. Syst., 1900, 13, p. 504) does not doubt the accuracy 

 as to the locaHty in view of the rarity of this species on the mainland, and the 

 fact that we know so httle of the estuarine fauna of all the islands. He empha- 

 sizes the fact that Tomistoma long existed undiscovered in both Sumatra and 

 Malay, and even suggests that the Malayan Gharial may exist in Java. I must 

 confess to a scepticism regarding the correctness of the data of the Frankfort 

 specimen. Werner may be correct, but if so, why is the crocodile not quite as 

 likely to occur in Sumatra, though as yet undiscovered? Geoclemys subtri- 

 juga (Schlegel and Miiller), the conspicuous and generally common Natrix pis- 

 cator (Schneider), the showy rat-snake Ptyas mucosus (Linne), so often common 

 about dwellings, and Dryophis xanthozona Boie, are all species known both from 

 Java and the mainland, and one would suppose that they would be among the 

 earliest to be discovered on Sumatra; but, so far as we now know, they do not 

 occur there. Agkistrodon rhodostoma (Boie) has long been known from Java, 

 and for years it was included in the Siamese fauna on the basis of a single speci- 

 men, said to be from Siam, preserved in the British museum. Within the last 

 few years Messrs. Annandale and Robinson during their exploration of the Malay 

 Straits discovered that it was quite plentiful in certain locaUties in the Malay 

 Peninsula. (Cf. Boulenger in FascicuU Malayensis, 1903, 1, p. 170-171.) It is 

 hardly less surprising that this conspicuous snake should have been so long 

 undiscovered in the Malay Peninsula than it would be if other species, equally 

 conspicuous, should perhaps be still undiscovered in Sumatra — this species 

 among them. The presence of Rhinoceros sundaicus, though comparable to that 

 of Agkistrodon, is even more difficult to explain. The Sumatran rhinoceros, 

 R. sumatranus, is well known, and occurs also on the mainland. It is difficult 

 to believe that of two species of rhinoceros existing in Sumatra, only one should 

 have been discovered up to now. Still this is probably the case, for we know as 

 yet very little definitely regarding the various Malayan species of rhinoceros (see 

 Flower, Proc. Zool. soc. London, 1900, p. 366-8). The cases of Tragulus stan- 

 leyanus, Viverricula malaccensis , and Helidus orientalis, all of which have been 

 noted by van Kampen as having the same discontinuous distribution, may be 

 considered as instances where specimens from the difTerent localities would not 

 be considered as identical species were plenty of modern material in hand for 

 comparison; besides, their close relatives may easily exist in the highlands of 

 Sumatra, which are as yet unexplored. Tragulus stanleyanus, I have been 

 recently informed by Mr. G. S. Miller Jr., is a species certainly confined to the 



