269 



a half as wide at its base as the ventral hook. The interval between both hooks is rounded 

 at the base and, as in Syn. acanthitelsonis, a fissure runs inward, soon dividing itself in two 

 other ones, the anterior of which runs obliquely towards the curved anterior margin of the joint. 

 One observes in the interior of the ventral hook also some narrow bands or stripes that curve 

 backward, just as in Syn. acanthitelsonis. In Syn. acanthitelsonis, hovvever, the ventral hook is 

 longer with regard to the dorsal and both hooks are equally broad at their base. These legs 

 are slisfhtly setose. 



Relative proportions of the fifth legs: merus 1,5; carpus i; propodus 1,43. The merus 

 is 3,6-times, the propodus 5,55-times longer than wide and the dactylus measures a little more 

 than one-sixth of the propodus. 



The larger specimen is almost 1 1 mm. long, the other 9,5 mm. 



f27. Synalpheus Patdsoni Nob. var. Raiucswarcnsis Cout. 



Alpheus sp. J. G. de Man, in: Zoolog. Jahrb. Abth. f. Syst. IX, 1897, p. 738, Fig. 62a and Ó2aa. 

 Synalplieus Paulsonï Ramesivarensis H. Coutière, in: Buil. Soc. Philom. Paris, (9) T. XI, 1908, p. 1 1. 



A new examination of one of the 6 specimens from Atjeh, described by me (1. c.) as 

 Alpkeus sp., which specimen, 13 mm. long, belongs to my private collection, proved it to 

 appertain to Syn. Paulsoni Nob. var. Ramesivarensis, a variety which occurs at Rameswaram, 

 near Ceylon. In the variety Rameswarensis the terminal spine of the scaphocerite should, as in 

 the typical Syn. Patdsoni, be longer than the carpocerite, in the Atjeh specimens, however, the 

 terminal spine extends as far forward as the carpocerite. The specimen which is lying before me, 

 accords with the quoted description, but the following measurements will still be welcome. 



The carpocerite is 3,4-times as long as wide. 



Measurements of the large chela : fingers i; chela 3,3; height 1,1. Chela 3-times as long as 

 high, palm terminating in a small, conical tooth that is directed straightly forward. Merus unarmed. 



Measurements of third legs: merus 2,4; carpus i; propodus 2. Merus 3,9-times as long 

 as wide, propodus 6-times, with 6 spinules on the posterior margin besides 2 at the distal 

 extremity; these spinules are 0,16 — 0,2 mm. long. 



Length of the telson 2,24-times as long as the posterior margin is wide; outer angles of 

 the latter spinous, but only reaching to midway the length of the posterior margin. Proportion 

 between the width at the base and that of the posterior margin 1,8. Spinules of the upper 

 surface 0,24 mm. long, one-eighth the length of the telson. Anterior pair of spinules nearly in 

 the middle, posterior pair a little farther distant from the posterior margin as from the anterior 

 pair; distances of both pairs from the posterior margin in proportion to one another as 1 :o,58. 



This form was not collected by the "Siboga". 



f28. Synalpheus gracilirostris de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 19 10, p. 291. 



Stat. 282. January 15/17. 8°25'.2S., I27°i8'.4E. Anchorage between Nusa Besi and the N.E.- 

 point of Timor. 27 — 54 m. Sand, coral and Lithothamnion. 2 specimens, 1 of 

 which is ova-bearin». 



137 



SIBOGA-EXPEDITIE XXXIX a'. 



35 



