FEOM THE INLAND SEA OF JAPAN. 431 



The mevus of the other chelipecl agrees with the dcscrihecl one, but there is no tooth 

 at the far end of the upper border and tliat of the inf ra-iuternal border is also rudimentary. 

 The wrist is a little longer than that of the left cheliped. 



This speeies now proves to belong to those of the " edwardsi" -section, in which the 

 dactylus of the smaller cheliped presents the " Balceniceps "-form in the male, whereas 

 that of the female is simple. M iers makes no mention of this character, but only two 

 specimens were at his disposal, probably females. Spence Bate was able to examine both 

 males and females ; but the difference was nevertheless overlooked by him, and his fig. 4 k' 

 represents apparently the smaller cheliped of a female. In both males the smaller chela 

 (PI. 33. fig. 53) is a little longer than the larger, and in both the fingers are somewhat 

 shorter than the palm. The straight upper margin of the palm, which distinctly narrows 

 distally, terminates in an acute lobe a short distance behind the articulation of the 

 fingers, but the lower margin has no constriction at all ; the longitudinal depressions on 

 the inner and on the outer side of the palm are distinct. Just as on the larger chela, 

 a sharp spine occurs on cither side of the articulation of the dactylus. The dactylus has 

 the well-known " Balteniceps "-form : two crests, which are beset with stiff setae and which 

 arise from the middle of the finger, run, on its outer and inner side, forward and upward, 

 and unite at a short distance behind the tip ; looked at from above the dactylus appears 

 here somewhat broadened, whereas it is narrowest in the middle. The fingers shut close 

 together, and their hooked tips cross one another. 



The larger cheliped of the female is wanting ; the smaller agrees with the figure 4 k' 

 in the ' Challenger' Report. The upper border of the merus is unarmed, but there is a 

 sharp tooth or spine at the distal end of the infero-internal margin. The fingers are 

 distinctly somewhat longer than the palm, and the slender tapering dactylus is simple, 

 without hairy carinse. Both the uppt;r and the lower border of the palm are enlire, 

 without a constriction or lobe behind the articulation of the fingers. The inner surface 

 of the larger chela is finely granulated ; the granules are wanting on the triangular 

 depression, on the middle of the palm, and at the base of the immobile finger, exce^jt iu 

 the middle ; the dactylus is smooth, except at its base. Tlie granulation on tlie outer 

 surface is less distinct. 



The carpu.s of the second pair of legs is 5-articulate ; the first joint is almost as long 

 as the tliree following taken together, the fifth is once and a half as long as the two 

 preceding, which are equal and the shortest of all. The fingers are a little longer than 

 the palm. The other legs are slender, smooth, unarmed. 



Eggs very numerous and small. 



The upper surface of the body and of the peduncles of the internal antenna;, as also 

 the inner surface of the chelipeds, are reddish. 



Couticre (" Les Alpheidaj," in Ann. Sc. Nat., Zool. 8"^ sdr. ix. 1899, p. 35) is inclined 

 to regard this species also as a variety of ^. eihcardsii, but I am not of that opinion. 



This Prawn is named the Clawcracker, because it makes a loud cracking noise with its 

 claws which can be heard under water : if the noise is made while the animal is bein"- 

 handled it is instinctively dropped, owing to the slight shock received. The exertion is 

 so great that the end of the big claw is frequently cast off. 



