1889.} DIFFERENT SPECIES OF OTTER. 191 
Dr. A. Nehring, of Berlin, Dr. von Lorenz, of Vienna, and Mr. 
J. W. Clark, of Cambridge, for assistance either by letter or by loan 
of specimens. This assistance has in many cases been of most 
material aid in making out the synonymy of the obscurer forms. 
Firstly, as to the genera which should be admitted within the 
subfamily Lutrine. Putting aside Enhydris as unquestionably 
good, and Barangia, Lontra, Nutria, Hydrogale, Latax, and Lutro- 
nectes of Gray’, and Leptonyx of Lesson, as unquestionably bad, 
we have only to consider Aonyx, Lesson? (syn. Anahyster, Murray *), 
and Pteronura, Gray 4 (syn. Saricovia, Lesson aye 
The first of these, Aonyx, was founded on the Cape Clawless Otter ; 
its generic characters depending on the lesser development of the 
webbing between the toes and on the reduction of the claws. The 
latter character also occurs, in a rather less degree, in the Indian 
Clawless Otter, which nevertheless, as Mr. Blanford has shown oP 
presents no special genetic affinity with the African form, a fact that 
quite disproves its generic value in the group. The skull and den- 
tition of Aonyx are wholly those of a true Lutra, and therefore I 
think it must be certainly amalgamated with that genus, of the 
members of which L. darang is apparently most closely allied to it. 
The characters of Pteronura, again, appear to be clearly of spe- 
cific and not of generic importance. The corded margin to the 
tail is only an exaggeration, suitable to so large a species, of the 
flattened state of that organ in other Otters; while in the remarkable 
narrowness of its frontal region, certainly the most peculiar character 
of its skull, this species does not differ from such narrow-fronted 
Otters as L. sumatrana or L. maculicollis to a greater extent than 
the latter do from the broad-fronted L. capensis, L. felina, and L, 
paranensis. 
The whole of the living species of Otters, excepting of course the 
Sea-Otter, appear therefore to be most correctly placed in one single 
genus only. This genus, Zuéra, has the widest distribution known 
among the non-volant Mammalia, its range extending over the whole 
globe with the exceptions of the Australasian Region, of Madagascar, 
and of the extreme Arctic and Antarctic poles. 
Pending the impossibility of drawing up a natural arrangement, 
the species may best be treated geographically. 
ORIENTAL OTTERS. 
The synonymy of the Oriental Otters is exceedingly confused, 
chiefly owing to Sir Stamford Raffles, in his account of the Mammals 
of Sumatra, having given native names, without descriptions, to the 
two species he found there, which names were afterwards differently 
applied by different authors to the three species actually occurring 
in that island. 
1 P.Z.8. 1865, pp. 123-133. 
® Man. Mamm. p. 157 (1827). 
* P. R. Phys. Soc. Edinb. ii. p. 158 (1860). 
* Charlesw. Mag. N. H. i. p. 580 (1837). 
5 N. Tabl. R. A., Mamm. p. 72 (1842). 
* Mamm. Brit. Ind. p. 188 (1888). 
