3 28 



m s Rostrum narrow, obtuse, subulate. Lobes terminating 

 the upper and the lovver margin of larger chela 



acute chiragricus H.M.Edw. 



4 Smaller chela of the male less than 4-times as long 

 as high, with both margins distinctly notched; lobes 

 terminating both margins of larger chela obtuse, 



rounded crassimanus Heller ') 



k. Merus of 3 rd legs more than 6-times as long as wide ; 



rarely 5, 4-times, but in this case the lower border 



of the larger chela hardly emarginate. 



/j Smaller chela of the male of a rather stout form, the 



proportion between length and height being 4 or less, 



with an acute tooth at either side of the articulation 



of the dactylus. 



m 1 Merus of 3 vd legs in adult specimens somewhat more 



than 6-times, in younger individuals almost 7-times 



as long as wide, with the extremity of the lower 



margin rather sharp pareuchirus Cout. 



m* Merus of 3 rd legs 5, 4-times as long as wide, with 

 the extremity of the lower margin rounded 



pareuchirus Cout. var. Leucothea de Man 

 /„ Smaller chela of the male at least 5-times as long as high, 

 carpocerite just as long as the antennular peduncle. 

 Merus of y d legs 7, 5-times as long as wide. 

 w, Frontal margin distinctly emarginate near the base 

 of the rostrum •, 2 nd antennular article a little longer 

 than the visible part of the i st ; larger chela 

 distinctly emarginate on the lower margin. . . leptochirus Cout. 

 (H. COUTIÈRE, Alpheidae Mald. and Laccad. Archip. 1905, p. 914, PI. LXXXVII, 

 fig- 54)- 



iu„ Frontal margin straight near the base of the rostrum ; 

 2 nd antennular article a little shorter than the visible 

 part of the i st ; larger chela with the lower margin 

 only slightly sinuous leptochiroides de Man 



1) It rernains uncertain whether the japanese A. lobidens de Haan is identical with A. crassimanus or not. I was unable to 

 examine the single type specimen of A. lobidens, that is still preserved in the Leyden Museum, but that, as Dr. Hokst informs me, 

 is broken and fragmentary. I was, however, enabled to study two specimens of the species referred by Dr. ORTMANN to A. lobidens 

 (in: Zool. Jahrb. V. Syst. 1890, p. 474, Tab. 36, tig. 13); unfortunately these specimens which I received frorn the Museum at Stiassburg, 

 were desiccated and in a bad state. Thcy bore a close resemblance to A. crassimanus, especially the legs of the i st pair, but those of 

 the 2" d were somewhat different. The merus of the 2" d legs proved to be 8,5-times longer than wide and the carpal segments were 

 1,8 mm.; 1,8 mm.; 0,52 mm.; o,4S mm. and 0,7 mm. long, the l st segment 5,6-times longer than thick at distal extremity. These legs 

 appeared therefore a little more slender than those of A. crassimanus and the 2" d segment was just as long as the i*<. The question 

 whether both species are different or not, must be left to further researches. 



196 



