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AUG 1? i'.;:i " 



X. A Contribution to Indian Carcinology. Bij J. 11. IIexdersox, 3I.B., F.L.S., 

 Felloio of the University of Madras, Professor of Biology in the Bladras Christian 

 College. 



(Plates XXXVa.-XL.) 



Read IGth June, U'-'92. 

 IXTRODUCTIOK. 



IHE Decapod and Stomatopod Crustacea referred to in this paper, thoug-h furnished 

 by several distinct collections, are all from Indian localities, and it has therefore been 

 found most convenient to incorporate the results of their examination in a single report. 

 A large proportion of the species are contained in two collections, both of considerable 

 size, the first formed by my friend Mr. Edgar Thurston, Superintendent of the Madras 

 Government Museum, chiefly from stations in the Gulf of Manaar, the second by myself, 

 from various localities in the Madras Presidency. Both collections were to some extent 

 examined and the species ideiititied in India, prior to my return to England on leave 

 in 1891, and I fully anticipated tliat a short period of work at the British Museum 

 would have enabled me to complete the identifications. But the time thus occupied 

 proved much longer than I had calculated, a large portion of it being taken ujj with 

 the examination of some of the commonest and longest known forms, which are certainly 

 not so well knoAvn as they ought to be ; and I may add that my later studies have con- 

 vinced me that the Avorking out of a large collection of shallow-water species cannot be 

 satisfactorily accomplished in India. 



"V^'hile engaged in this work, Dr. Giinthev and Mr. Pocock, of the British Museum, 

 kindly placed in my hands for examination a series of Indian Crustacea deposited in 

 the National Collection, including a large number of specimens presented by the late 

 Surgeon-General E. Day, CLE., and Mr. E. W. Gates, E.Z.S., which liave enabled me 

 considerably to enlarge the scope of this paper. Dr. Day's collection consists chiefly 

 of the larger and better known Indian marine Decapods, from various localities, as well 

 as a number of laud and freshwater Crabs (Telphusidcc), and a large series of freshwater 

 and marine Pi*awns, belonging to the genera Balcemon and Pencens, which have indviced 

 me to revise, to some extent, the characters of the Indian sjiecies belonging to the latter 

 genus. Mr. Gates's collection, though not of large extent, includes a number of most 

 interesting forms — principally Macrura — taken by dredging at depths of from tea to twentv 

 fathoms, in the Gulf of Martaban, Burmah ; and, as might 1)6 expected, it contains some of 

 the species lately described by Dr. De Man, from the neighbouring Mergui Arehijielago. 

 In addition to these 1 have examined two small collections from Ceylon, the ^lirst 

 consisting of between fifty and sixty species, which were sent me for identification 



SECOND SERIES. — ZOOLOGY, VOL. V, 18 



