118 Records of the Indian Museum. [Vor. VIE, 
characters of the mouth parts, in the relative length of the peraeo- 
pods and the spinulation of their meral and carpal segments, in 
the branchial formula and in the armature of the telson there 
appears to be the closest possible resemblance between the two 
forms. 
In point of fact, the sole difference that I have been able to 
discover is one of colour. In the majority of the New Zealand 
specimens received from Dr. Chilton the proximal part of each of 
the setae which fringe the antennal scale and uropods is bright 
purple and the same coloration is found on the terminal spinules 
of the telson. This curious pigmentation undoubtedly vanishes 
in alcohol and, although it is well shown in most of Dr. Chilton’s 
specimens, which were collected in 1910, it could hardly be ex- 
pected to have persisted in the examples from Assam which have 
been lying in alcohol for many years. 
Xiphocaridina curvirostris was first described by Heller (1862) 
as aspecies of Caridina from specimens obtained at Auckland. A 
fuller account by the same author appeared in 1865 and in 1876. 
Miers included it, also under the genus Carzdina, in his Catalogue 
of New Zealand Crustacea. Three years later (1879) Thomson des- 
cribed it as a new species of Palaemonidae, Leander fluviatilts ; 
but in 1903 he realized his mistake and gave a fresh account of it! 
under the name Xiphocaris curvirostris. In Ortmann’s revision of 
the Atyidae (1895) it appears as Caridina curvirosiris with a note 
to the effect that it probably belongs to the genus Xzphocaris. 
Bouvier does not refer to the species in his valuable paper published 
in 1905; but he mentions it subsequently—using Thomson’s name, 
fluviatilis—as a member of his new genus Xzphocaridina (1909, 
a, b). 
The curious distribution of Xiphocaridina curvirostris does 
not, I believe, find any exact parallel among other freshwater 
Crustacea. 
Perhaps its most peculiar feature is that the other species of 
the genus, X. compressa, which inhabits S. Australia, Flores, China, 
Korea and Japan appears to extend in a band completely separat- 
ing the two localities in which it is known to exist. But in the 
present state of our knowledge it is impossible to lay any emphasis 
on this point, for it may well be that X. curvirostris still remains to 
be discovered in many other localities. 
On turning to Ortmann’s work on ‘‘ The geographical distribu- 
tion of freshwater Decapods and its bearing on Ancient Geography ”’ 
(1902) it is at once seen from the maps illustrating the hypotheti- 
cal distribution of land and sea in past geologic periods that, 
according to this author’s views, no direct land connection be- 
tween New Zealand and Assam has existed in any recent epoch. 
In the Lower Cretaceous, however, when a land-bridge connected 
S. India with Madagascar and S. Africa, and when the whole of 
Northern India was submerged and formed the eastern limit of the 
1 The figures given on Pl. xxix are poor. 
