spines at the distal extremity included, and 7-times as long as broad at its base ; it bears the 

 usual, transverse rows of setae and 3 or 4 spines at the distal extremity. 



One of the two females has lost both chelipeds, the other supports still the right, and 

 another cheliped is lying loose in the tube : these two chelipeds are equal. This fact, of course, 

 does not exclude that the chelipeds may be subequal in the female, because the detached leg 

 perhaps belongs to the other specimen. The two chelipeds are leather feeble and somewhat 

 resemble those of Alph. aeqttalis Cout. Of the detached cheliped the ischium is rather slender, 

 5-times as long as thick distally. The merus which is one and two-thirds times as long as the 

 preceding joint, is also slender and also about 5-times as long as thick at the distal extremity, 

 while the slightly curved joint gradually thickens toward the far end ; the distal angles are 

 obtuse, not acute as in Alph. aegtialis. The carpus is short, one and a half as long as thick 

 and measures one-third the length of the merus ; as in Alph. aequalis one observes a feeble 

 transverse groove near the articulation of the chela. Chela 4-times as long as the carpus and 

 two-fifths longer than the merus. The palm which is very slightly shorter than the fingers, 

 appears a little more than twice as long as high, is somewhat compressed and shows no 

 grooves at all, the two margins running parallel with one another; the cutting-edges of the two 

 fingers that shut close together, bear a very small tooth near the tips, while one observes more- 

 over on the cutting-edge of the immobile finger 3 or 4 similar, minute teeth along the middle, on 

 that of the dactylus i or 2. This leg is almost 4 mm. long, two-fifths the length of the body. 



Second legs slender. The very slender ischium is 1 4-times as long as thick, the merus 

 which is one-seventh shorter, 1 2-times. Carpus 1,45-times as long as the merus; the five seg- 

 ments are respectively 0,62 mm., 0,3 mm., 0,26 mm., 0,26 mm. and 0,3 mm. long. The first 

 segment which is 7-times as long as thick distally, appears twice as long as the second and 

 as the fifth that are equal, while the third and the fourth are also equal and a little shorter 

 only than the second and the fifth; the second segment is 3-times, the fifth 2,2 2-times as long 

 as thick. The chela, the fingers of which are a little longer than the palm, is just half as long 

 as the merus and as long as the first segment of the carpus. 



The third legs resemble those of Alph. trispinosns (Stimps.) (H. Coutiere, Les Alpheidae, 

 1899, p. 259, Fig. 315). The slender ischium is armed with a movable spine in the middle 

 and with another behind it. The measurements of the three following joints are : merus i ,9 ; 

 carpus I; propodus 1,8. Merus 8-times, propodus ii-times as long as wide, the propodus with 

 6 feeble spinules along its whole length and 2 or 3 longer spinules at the distal extremity. 

 Dactylus simple, measuring only a little more than one-third of the propodus, slender, 7-times 

 as long as broad at its base, slightly curved. The fifth legs are missing. 



Ova few in number, 0,6 mm. long. 



Length 10 mm. 



J 3. Alpheopsis Sibogae de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1910, p. 307. 



Stat. 49\ April 14. 8°23'.5S., II9°4'.6E. Sapeh-Strait. 70 m. Coral and shells, i specimen. 

 This remarkable species is at once distinguished by the characteristic shape and position 



49 



SIBOGA-EXPEDITIE XXXIX rt '. 24 



