136 Mr. A. Alcock on 



XXII. — Natural History Notes from H.M. Indian Marine 

 Survey Ship ^ Investigator^^ Commander T. H. Heming^ 

 R.N., commanding. — Series II., No. 25. A Note on the 

 Deep-sea Fishes^ loith Descriptions of some new Genera and 

 Species, including another probably Viviparous Ophidioid. 

 Bj A. Alcock, Surgeon-Major I. M.S., Superintendent of 

 the Indian Museum. 



Contents, 



§ 1. Introduction. 



§ 2. On some Geographical Relations of the Deep-sea Fish-fauna of 

 India. 



§ 3. General Composition of the Deep-sea Fish-fauna of India. 



§ 4. Descriptions of new Species, including another probably Vivi- 

 parous Species of Dijylacanthojwma. 



§ 1. Introduction. 



In the Ann. & Mag. Nat. Hist, for November and December 

 1889, September and October 1890, January, July, and 

 August 1891, November 1892, and August 1895, and in the 

 ' Journal of the Asiatic Society of Bengal ' for 1893, 1894, 

 and 1896, I have described the fislies dredged by the ' Inves- 

 tigator ' in depths ranging from 100-1800 fathoms during the 

 twelve years 1885-1896. 



In the present paper some noteworthy species dredged since 

 1896 are recorded ; though two of these {Raja Powelli, sp. n., 

 and Monocentris japonicus, C. V.) were taken at a depth less 

 than 100 fathoms, yet the occurrence of a temperate genus 

 like Raja close to the Indian shores, and the addition of 

 another singular Japanese species to the Indian fauna, are 

 sufficiently interesting to be noticed here. 



§ 2. On some Geographical Relations of the Deep-sea 

 Fish -fa una of In dia . 



In my earliest paper (Ann. & Mag. Nat. Hist., Nov. 1889, 

 p. 379) on the deep-sea fishes of the Indian region I drew 

 attention to the fact tliat several of our species were common, 

 on the one hand to the deeper waters of Madeira, the Medi- 

 terranean, and the Atlantic coasts of America, and, on the 

 other hand, to the seas of Japan. 



As Dr. Giinther had, long before, noticed the correspon- 

 dences between (1) the Madeiran, Mediterranean, and West- 

 Indian fish-fauna, and (2) the fish-fauna of Japan, and as at 



