345 



of 1899, but the hairy groove on each side of the dactylus reaches but little beyond the middle; 

 the smaller chela agrees also with the figure 272. This specimen bears only the right leg 

 of the 2 nd pair; the carpal segments measure 1 mm., 3,4111111., 0,8 mm., 0,9111111. and 1,3111111.; 

 the chela is 2,1 mm. long (fingers 0,94111111., palm 1,16 mm.). Merus of 3 ,d legs 4 mm. long 

 and 1,06 mm. wide in the middle; the carpus (2,8 mm.) is a little longer than the propodus 

 (2,5 mm.), when measured between the two articulations, and the propodus bears 5 spinules, 

 besides 4 on its outer surface. According to Coutière (1. c. 1905) the carpus should be slightly 

 shorter than the following joint. Telson 2,7 mm. long, posterior margin 0,74 mm. wide, greatest 

 width 1,66 mm. 



In the egg-bearing female from Stat. 125 the rostrum (0,17 mm.) is almost half as long 

 as the visible part (0,4 mm.) of i st antennular article; the 2 nd article (0,64 mm.), somewhat 

 more than one and a half as long as the i st , appears almost half as broad as long, this joint 

 being 0,31 mm. thick in the middle. The two peduncles are of equal length, the scaphocerite 

 a little longer. 



The young male from Stat. 144 is 13 mm. long. Second antennular article 0,52 mm. 

 long, half as thick as long, and little longer than the visible part (0,4 mm.) of the i st . Rostrum 

 one-fourth of the i st article. In this male the grooves on the dactylus of the larger chela are as 

 long as in Coutière's figure 271. The carpal segments of the left leg of the 2 nd pair are 0,6 mm., 

 1,96 mm., 0,48 mm., 0,5 mm. and 0,84 mm. long, the chela is 1,43 mm. long (fingers 0,65 mm., 

 palm 0,78 mm.). The carpal segments of the other leg are 0,52 mm., 1,4 mm., 0,4 mm., 0,4 mm. 

 and 0,67 mm. long, the chela 1,2 mm. (fingers 0,54 mm., palm 0,66 mm.). 



Remarks. A. obcso-manus Dana differs by the following. In this species the scaphocerite 

 is considerably shorter than the antennular peduncle, hardly reaching beyond the 2 nd article. 

 The larger chela bears 110 furrows at all. The 2 Qd carpal segment of the 2 nd legs is comparatively 

 longer, 4-times as long as the i st and longer than the three following segments and the 

 chela taken together, while in A. microstyhis it is shorter than the sum of these joints. 



General distribution: Albany Island near Cape York (Spence Bate); Pulo Edam 

 (de Man); Hulule Male Atoll (Coutière); Djibouti (Coutière); Mascate (Coutière). 



f 11. Alpheus microstylus (Sp. Bate) var.? 



Stat. 40. April 2. Anchorage off Pulu Kawassang, Paternoster-islands. Coralreef. One male, 

 probably young. 



This specimen closely resembles A. microstyhis, but differs from the specimens referred 

 to this species by the more slender shape of the legs of the 2 nd pair and by the telson 

 tapering more back w ar d. This specimen is 10 mm. long. Rostrum acute, measuring one- 

 third the visible part of i st antennular article. Second antennular article one and a half as long as 

 the visible part of the i st and 2,5-times as long as thick; 3 rd article as long as i st . Scaphocerite 

 as lono- as the antennular peduncle, antennal peduncle reaching almost to the extremity of 

 3 ld antennular article; the scaphocerite resembles that of A. microstylus, but its width is only 

 one-fourth of its length. 



2I 3 



