I9I7.] 



S. Kemp : l^otes on Crustacea Decapoda. 



47 



proximal end of the propodus, there is (in both sexes and in all 

 four species) a patch of short barbed spinules, which, when the 

 segments are flexed, forms a sort of grasping organ. 



The merus and carpus of the second pair are about equal in 

 length' ; the carpus is from it to 1*3 times as long as the chela. 

 In the third peraeopods the merus is a little shorter than the 

 carpus and a little longer than the chela. The carpus is from i"3 

 to I "4 times the length of the chela. In the male, in the position 

 normally occupied by the fourth pair of legs, there are two bluntly 

 pointed and forwardly directed processes. 



The branchiae resemble those found in the genus Sergestes and 

 do not appear to afford any specific differences in the four forms 

 under consideration. The formula is: — 



This formula agrees with that given by Ortmann* except that 

 a small podobranch is present at the base of the second maxilli- 

 pede. This branchia is perhaps absent in the Atlantic species 

 that Ortmann examined. 



Arranged according to length, the order of the abdominal 

 somites is 6, 4, i, 3, 5, 2 ; the sixth is about twice the length of 

 the fifth and its greatest breadth is from i'6 to 2'0 times its length. 

 The sixth somite is provided with a single very small spinule, 

 placed dorsally on the posterior margin. The telson is sulcate 

 above and is much shorter than the inner uropod. 



Genus Acetes, Milne-Edwards. 



1830. Acetes, Milne-Edwards, Ann. Sci. nat., Pan's, XIX, p. 350. 

 1837. Acetes, Milne-Edwards, Hist. nat. Crust., II, p. 429. 



Acetes indicus, Milne- Edwards. 

 (Text-figs. ia,b, 2(7, 3«, 4a, 5c, ja.) 



iSt,o. Acetes indicus, Milni-Edwards, Ann. Sci. nat., Paris, XIX, p. 351, 

 pi. xi, figs. 1-9. 



1837. Acetes indicus, Milne-Edwards, Hist. nat. Crust., II, p. 430. 

 ? 1852. Acetes indicus, Dana, U.S. Explor. Exped., Crust., I, p. 608. 

 ? 1890. Acetes indicus. Walker, jfourn. Linn. Soc, Zool., XX, p. 112. 

 ? 1893. Acetes indicus, Henderson, Trans. Linn. Soc, Zool. (2), V, p. 452. 

 ? 1905. Acetes indicus, Pearson, Ceylon Pearl Oyster Rep., IV, p. 75. 



i The merus is a shade longer than the carpus in A. japonicus and .4. 

 erythraeus, a trifle shorter than the carpus in A. indicus and A. insularis. 

 2 Ortmann, Decap. Schizop. Plankton. Exped., p. 39 (1893J. 



