TO INDIAN CAECINOLOGT. 333 



of a large number of the marine species — which from time to time ai-e discovered 

 in widely separate localities — is appai-ently to a great extent determined by th(> dis- 

 tribution of coi'al reefs, and as regards the higher Crustacea, at least, any attempt to 

 svxbdivide the large central or coral-reef region of the Indo-Pacific area seems of douhtful 

 value, and we can scarcely seek for natural subdiv"isions till we pass into the tcuipci-atc 

 and colder waters, north and south of the coral rec'ion. Nearly two tliirds of the total 

 number of species recorded in this paper are known to occur in the seas of tlie Malay 

 Archipelago; about one third occur at Mauritius or the neighbouring islands; the same 

 proportion in the seas of North Australia, and a slightly greater number in the islands 

 of the Pacific (New Caledonia, Eijis, Samoa, Sandwich Is., &c.). Nearly one fourth of 

 the number occur at Japan ; while one fifth are found in the Ked Sea, the same pro- 

 portion on the east coast of Africa, and about the same in Australian localities excluding 

 those on the north coast. Not less than twenty-seven of our species occur on the 

 coast of Natal, and at least thirteen iu the seas of New Zealand ; while eight extend 

 their range into the Atlantic area. The same amount of attention has not been paid l)y 

 collectors to each of these regions, some having been more specially favoured ; but, in 

 spite of this, there can be no doubt of the great affinity between the Indian and Malayan 

 Crustacean faunas. 



The distribution of the freshwater species offers certain points of interest. The genus 

 Tel]:i]nisa has repres(>ntatives in South-Eastern Asia (Malay Archipelago, ^lalay Peiiiusula. 

 and China) of what may be termed a granulated group of species ; in Burmali and Upper 

 India similar forms are met witli, e. g. T. Atkinsoniana, AVood-Mason, and T. Feallnna, 

 Wood-Mason, which so far as is known do not extend tlieir range into the Indian 

 Peninsula*; while turther west, in Beloochistan and Persia, tlie allied T. jlaviatiUs 

 makes its appearance, and finally spreads along both sides of the ^lediterranean. The 

 genus Faratelpluisa has a somewhat similar range, extending from the Malay Archi- 

 pelago along the Malay Peninsula into Burmah and Northern India, but no species 

 have yet been recorded from Soutli India or Ceylon. Very little is as yet known 

 of the Indian species of Palcenion, but there can be no doubt that they are very 

 numerous. P. scabricukis, a very Avell-marked species, described originally from Ceylon, 

 occurs in Upper India and in the IMahiy Archipelago ; it, however, remains to Ije seen 

 whether it does not also occur in Burmah and the Malay Peninsula. The mark(,'(l 

 prevalence of freshwater prawns in the streams of South-eastern Asia and the Malay 

 Archipelago, with the apparently complete absence of crayflsl\ from the same region, 

 seems to strengthen Professor Huxley's suggestion tliat the latter have been displaced 

 by better fitted competitors. The genus Carklii/a is represented at Madras, and 

 probably elsewhere in India, l)y a species whieli i am unable to separate from 

 C. If'yckii, described by Jlickson from Celebes, and which itself is perhajjs not distinct 

 from a longer-known species, found in North and Kast Africa, a remarivai)ly extended 

 range for a fresh-water species. 



* III the Briti>li .Museum tliere is a specimen of T. Athinsonianu from Oeyloii. 

 SECOND SERIES. — ZOOLOGY, VOL. V. 4!) 



