A DESCRIPTION OF THE DEEP-SEA FISH CAUGHT BY 

 THE R.I.M.S. SHIP "INVESTIGATOR" SINCE THE YEAR 1900, 

 WITH SUPPOSED EVIDENCE OF MUTATION IN MALTHOPSIS. 



By R. E. lyi^OYD, M.B., Û.Sc. (Lond.), Capt., I. M.S., Acting Professor of Biology, 

 Medical College, Calcutta, formerly Surgeon Naturalist, Marine Survey of India. 



Four years ago Colonel Alcock drew my attention to the fact that a number of 

 unknown fish had been obtained of late years by the " Investigator." The descrip- 

 tion of these had been delayed until the results of the German exploratory vessel 

 '' Valdivia/' which operated in deep waters round India, had been published. 



Colonel Alcock's catalogue of the deep-sea fish taken by the '' Investigator " was 

 published ten years ago. Since then a few new forms have been described from time 

 to time. Dr. Annandale has asked me to include these descriptions and to mention 

 the more interesting of the known forms obtained since the compilation of the cata- 

 logue, some of which have not been previously recorded from Indian seas. The 

 previous descriptions have been given verbatim so that the whole may form an 

 appendix to the catalogue published in 1899. Five genera and nineteen species are 

 described here for the first time. 



Systematic work cannot always be pursued with unbroken facility. There are 

 among the collection four small communities of the genus Malthopsis. These include a 

 number of types which although distinct, cannot I think be treated as separate species 

 in the ordinary sense of the word, for it is hardly possible to suppose that these types 

 arose in separate areas and subsequently came together again so as to exhibit the 

 remarkable distribution obtained. This question is dealt with separately at the end 

 of the systematic part of the paper. 



L SYSTEMATIC PART 



Subclass ELASMOBRANCHII. 



Order PLAGIOSTOML 



Suborder Selachii. 



Family SCYI^LID^. 



Scylliorhinus indiens, Brauer. 



Wissen. Ergebn. DeîUsch. Tiefsee-Exped. "Valdivia," Bd. xv, part i, p. 8, pL 

 xiv (1906). 



One specimen 30 cm. in length from 604 fathoms in the Gulf of Oman, Station 

 339. Registered No. i^^- 



