Before this, however, Dr. Armstrong had left the Survey, and it was not until the end of the year 

 1884, when Commander A. Carpenter, R. N., was appointed to the command of the ' Investigator,' and 

 Surgeon ( now Major) G. M. J. Giles, I.M.S., to the post of Surgeon-Naturalist, that deep-sea dredging 

 became a recognized, if subordinate, branch of the ship's routine. 



Since 1885 the Zoological collections made by the ' Investigator' have been year by year accumu- 

 lating in the Indian Museum, where, in accordance with the recommendations of the Council of the 

 Asiatic Society of Bengal, they have been deposited. 



It must not, however, be supposed that deep-sea dredging occupies a very large part of the 

 attention of the officers of the Survey ; since, as a rule, it is only possible when the ship is proceeding 

 to and retm-ning from her systematic surveys of the shores and shallows. It is rarely indeed that as 

 many as twenty deep-sea hauls are made in one year. 



From October 1888, when regular records began to be kept, up to the present time, 113 more or 

 less successful hauls have been made in depths of over a hundred fathoms (100-1997 fms.) : of these 

 71 have been under the superintendence of Captain A. E. S. Anderson, I.M.S., who has been Surgeon- 

 Naturalist since 1893. 



As regards the ' Investigator ' herself, she is a paddle-steamer of 580 tons, and for a few facts as 

 to her history and equipment I may refer to a paper in the Scientific Memoirs of the Medical 

 Officers of the Army of India for 1898. 



With regard to the contents of the present Eeport on the Brachyura, I may mention that the 

 species that are not here described for the first time have already been noticed in the following paper.?, 

 relating to the Indian Fauna : — 



J. Wood-Mason in Ann. Mag. Nat. Hist., May, 1877, p. 422 : in Proc. As. Soc. Bengal, August, 

 1885 : in Journ. As. Soc. Bengal, Vol. LVI, pt. 2, 1887, p. 206, pi. i : and in Ann. Mag. Nat. Hist., 

 March, 1891, pp. 258-270. 



A. Alcock in Ann. Mag. Nat. Hist., May, 1894, pp. 400-409 : and in Materials for a Carcino- 

 logical Fauna of India in Journ. As. Soc. Bengal, Vols. LXIV, LXV and LXVII, pt. 2, 1895, 

 1896, J 898. 



A. Alcock and A. E. S. Anderson in Journ. As. Soc. Bengal, Vol. LXIII, pt. 2, 1894, pp. 

 175-185 : and in Ann. Mag. Nat. Hist., Jan., 3899, pp. 5-14. 



A. E. S. AjfDERSON in Journ. As. Soc. Bengal, Vol. LXV, pt. 2, D896, pp. ]02-106. 



Illustrations of the Zoology of the R. I. M. S. " Investigator " by Wood-Mason, 

 Alcock, and Anderson, Crustacea, pi. v. xiv. xv. 3vi. xvii. xviii. xis. xx. xxi. xxii. xxiii. xxiv. xxv. 

 (xxxvi. xxxvii. xxxix. xl. in the press). 



The illustrations, like those of the Account of the Deep Sea Madreporaria, have been drawn here 

 by Baboos Abhoya Churn Chowdry and Shib Chunder Mondul, and reproduced in collotype by Messrs. 

 Taylor and Francis of London, 



A. ALCOCK, Major, I.M.S., 

 Superintendent of the Indian Museum. 



