1919-] S. Kemp : Notes on Crustacea Decapoda. 309 



In recent years a large number of specimens of Scopimerinae 

 have been added to the collection of the Zoological Survey of 

 India. We are indebted to Lt.-Col. C. R. Stevens, I.M.S., for a most 

 valuable series from Karachi, comprising examples of several new 

 and scarce forms. Lt.-Col. H. J. Walton, I. M.S., has contributed 

 further specimens of Dotilla blanfordi, hitherto known only from 

 the types, and Mr. J. Hornell, a small but interesting collection 

 from Tuticorin. I have to thank Dr. F. H. Gravely for a very 

 long series of Dotilla intermedia from the Orissa coast, material 

 which has enabled me to demonstrate the existence of dimorphism 

 among the males. Dr. J. G. de Man has kindly sent me examples 

 of Tympanomerus pusillus, Dr. Nakazawa and Dr. Bruno Parisi 

 specimens of Scopimera globosa. 



Excluding llyoplax, which cannot be recognised with certainty 

 until the type species has been rediscovered, the genera of Scopi- 

 merinae may be distinguished by the following characters : — 



I. Penultimate segment of 2nd maxilliped greatly ex- 

 panded, with ultimate segment applied to it laterally 

 as a narrow strip (text-fig. la). 



A. A conspicuous brush of hairs, indicating the posi- 



tion of the accessory branchial orifice, between 

 bases of ist and 2nd walking legs ; 4th segment 

 of abdomen not overlapping 5th, nor with a brush 

 of hair at its distal end ; abdomen of male with 

 4th or 5th segments constricted, the 5th occa- 

 sionally linear. [Lateral walls of carapace 

 usually without conspicuous sculpture.] ... Scopimera, p. 310, 



B. No brush of hairs between bases 'of walking 



leys; 4th segment of abdomen overlapping 5th 



and with a thick brush of hair at its distal end 



in both sexes ; abdomen of male not constricted. 



[Lateral walls of carapace with deep convolute 



sculpture' ... .. ... ... Dotilla, p- ^,24. 



IL Penultimate segment of 2nd maxilliped not expanded, 

 with ultimate segment attached terminally (text-fig. 

 lb). [4th segment of abdomen not overlapping 5th, 

 nor with a brush of hair at its distal end.] 



A. Lateral walls of carapace with deep convolute 



sculpture; upper surface strongly sculptured; 

 4th segment of abdomen of male remarkably 

 expanded, nearly 3 times as broad as fifth . Dotillopsis, p. 334. 



B. Upper surface and lateral walls of carapace not 



conspicuously sculptured ; 4th segment of abdo- 

 men of male not remarkably expanded though 

 it may be broader than 5th ... ... Tympanomerus, 



The tympana are well-defined and usually conspicuous in 

 Scopimera and Dotilla, ill-defined in Dotillopsis and ill-defined or 

 absent in Tympanomerus. The merus of the third maxilliped is 

 longer than the ischium in Dotilla and Dotillopsis and longer than 

 or equal to the ischium in Tympanomerus ; in some but not all 

 the species of Scopimera the ischium is longer than the merus. A 

 dense tomentum is found on the first three walking legs in 

 Dotillopsis and similar but less extensive patches of hair are found 

 in certain species of Tympanomerus. 



