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in Syji. hastilicrassiis, though the upper angle is acute. One of them, a female long 1 1 mm., 

 bears ova that are 0,88 mm. long. The telson agrees with the preceding specimen, but the two 

 pairs of spinules are situated farther from one another, the proportion between the distances 

 of either pair from the posterior margin being 1,83, instead of 1,6. 



Merus of large cheliped 2,4-times, that of the other 2,76-times longer than wide and 

 in each merus the upper margin ends in a small acute tooth. Proportions of the large chela : 

 fingers i; total length 4,2; height 1,56; proportions of the small chela: fingers i; total length 

 2,62 ; height 0,92. Proportion between the length of both chelae 2,5. 



Relative dimensions of the third legs: merus 2,8; carpus i; propodus 2,3, the latter 

 with II spinules, long 0,1 mm.; proportion between the length of the merus and that of the 

 propodus 1,2. Dactylus one-fifth the length of the propodus. 



General distribution: Maldive and Laccadive Archipelagoes. 



726. Synalpheus ancistrorhyncfnts de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1909, p. 124. 



Stat. 273. December 23/26. x^nchorage off Pulu Jedan, East coast of Aru-islands. (Pearl-banks). 

 13 m. Sand and shells. 2 males. 



A new species of the Paiilsoni group, related to Sy7i. acanthitelsonis Cout. 



Rostrum short, twice as long as wide at its base and reaching to the middle of the 

 visible part of first antennular article; the frontal spines, which are separated from the rostrum 

 by intervals rounded at their base, are slightly shorter and the three spines are curved 

 upward at their tips, like barbed hooks (i'-yxturpov). The obtuse, rostral carina is continued 

 to a little behind the corneae, disappearing here gradually. 



Antennular peduncle 4,3-times longer than thick at the distal end of median article; 

 median article a little longer than thick, measuring three-fourths of the length of the visible 

 part of basal article, third article a little shorter than the second. Stylocerite acuminate, reaching 

 to the 2^^ third part of median article. Lower spine of basicerite just as long as the stylocerite, 

 not shorter, in the younger specimen even slightly longer. The carpocerite, 4,3-times longer 

 than wide, surpasses the antennular peduncle by two-thirds the length of the third article, upper 

 spine of the basicerite small, curved upward and outward. The terminal spine of the scaphocerite, 

 the outer margin of wJiich is slightly concave, surpasses the antennular peduncle, but is shorter 

 than the carpocerite and exceeds by half its length the narrow scale that hardly reaches the 

 end of median article. 



All the abdominal pleura terminate in a triangular point, that is rather acute in the 

 3id — ^th^ iggg gQ jfi thc others; the anterior angle of the third is also acute. 



The telson much resembles that of Syn. acanthitelsonis Cout., but it narrows more 

 considerably backward, the length being 2,42-times as long as the width of the posterior 

 margin and the proportion between the latter and the greatest width being 2,1; the posterior 

 angles are prolonged to triangular spines, which project by half their length beyond the 

 median part of the margin. The two pairs of spinules of the posterior margin are nearly of 



135 



