Preface. 



In An Account of the Deep-Sea Brachyura collected by the Royal Indian 

 Marine Survey Ship Investigator published by the Trustees of the Indian Museum 

 in 1899, and in the Scientific Memoirs by Medical Officers of the Army of India for 

 the same year, I have explained something of how, and under what limitations, 

 the " Investigator " collections have been made. 



In the present memoir the Decapod Crustacea of the suborders Macrura and 

 Anomala are included, to the number of 169 species. The species of the suborder 

 Brachyura, treated elsewhere, number 58 ; so that the total number of species of 

 Decapod Crustacea collected by the " Investigator " in the depths of the seas 

 of India, up to the end of the year 1900, amounts to 227. 



This memoir, like the Catalogue of Investigator Deep-Sea Fishes published 

 in 1899, is very far from being a mere reprint of earlier-published reports. In 

 addition to tables and descriptions of species, it contains tables and definitions 

 of all the genera and subgenera, families, tribes, and suborders under which the 

 several species are arranged, and it embodies a large amount of material that 

 I have prepared for the basis of a more comprehensive work on Indian 

 Crustacea. 



As most of the Crustacean types discovered by the " Investigator " have 

 already been figured in the Illustrations published under the authority of the 

 Director of the Royal Indian Marine, the only figures that are appended to this 

 memoir are those of a few species that have escaped notice in that serial. 



A. Alcoce, Major, I.M.S., 



Superintendent of the Indian Museum. 



