1912. | 5S. Kemp: Notes on Decapoda. 115 
Xiphocaridina curvirostris (Heller). 
New Zealand; Chatham Is. 
Palaemontas gantert (Hay). 
Mammoth cave, Kentucky. 
It is consequently a matter of some considerable interest that 
one of these primitive Atyidae still persists in India, and the 
identification of this species with Xzphocaridina curvirostris, 
hitherto known only from New Zealand, presents a difficult prob- 
lem in geographical distribution. 
The material available consists of the following specimens ;— 
Tezpur, Darrang District, Assam. Col. H. H. Godwin-Austen. 
Twenty-four specimens, two of which are ovigerous females, rang- 
ing in length from 24 to 42 mm. 
Manipur Hills, Manipur state. Col. H. H. Godwin-Austen. 
Three specimens (none ovigerous ) from 24°5 to z8 mm. in length. 
These examples were found many years since and it must, 
I think, be the case that the species is very strictiy localised. 
Ona visit to Assam a year ago I had ample opportunities of 
collecting freshwater crustacea at Mangaldai in the Darrang Dis 
trict and on the neighbouring Assam-Bhutan frontier, localities at 
no great distance from Tezpur. Special efforts were made to 
rediscover Xiphocaridina ; but the search proved quite unavailing, 
although several interesting species of Cavidina were obtained in 
abundance in the tributaries of the Brahmaputra. 
For assistance in the identification of the specimens collected 
by Col. Godwin-Austen I am under considerable obligation to Prof. 
KE. L.. Bouvier, who was kind enough to forward me a transcript 
of one of his papers on Atyid evolution that had not at that time 
been received in our Calcutta libraries. He also furnished me with 
several references which afforded valuable information and spared 
me from his small series in the Paris museum a specimen of 
X. curvirostris from New Zealand for comparison with the Assam 
examples. 
Subsequently, Dr. C. Chilton, to whom I wish to convey my 
sincere thanks, furnished me with a considerable number of speci- 
mens, obtained in the R. Avon at Christchurch, New Zealand. 
I have thus been able to make a careful comparison of Indian 
and New Zealand examples and no doubt whatever remains in my 
mind of the complete identity of the two forms. Inasmuch, how- 
ever, as this determination raises questions of geographical distri- 
bution of no little importance a mere statement of fact would not 
perhaps be acceptable and in searching for some standard of com 
parison between the two forms it has seemed best to adopt the 
somewhat laborious method of measurements, as employed by de 
Man (1908) in the discrimination of varieties of Caridina nilotica. 
The figures are shown in the tables on pp. 116—117 and it will be 
seen that, judged by this criterion, there is no room for doubt 
regarding the identity of the forms from the two localities. In the 
proportions of the antennular peduncle and antennal scale, in the 
