i85 



telson being as i 10,57; posterior pair but a trifle farther distant from the extremity of the 

 telson as from the anterior pair. 



Antennular peduncle stout, resembling that of Alph. aeqttalis Cout. var. trtmcatus 

 Cout. (Alpheidae Maid, and Lace. Archip. 1905, p. 869, Fig. 139); the second article which 

 is a little wider than long, appears a little longer than the visible part of the first and than 

 the third article ; stylocerite acute, similar to that of the variety trtincat7is, but reaching only 

 to the middle of second antennular article or hardly beyond it. Basicerite with a rather large, 

 acute, triangular tooth or lobe at the lower side ; carpocerite stout, a little more than twice 

 as long as thick and reaching about to the middle of third antennular article ; antennal flagellum 

 nearly twice as long as the carapace. Scaphocerite as long as the antennular peduncle, very 

 broad like in Athanopsis, with the terminal spine very small, curved inward and not reaching 

 beyond the rounded, anterior margin of the scale. 



Merus of second legs 7-times as long as wide. Carpus 1,3-times as long as the merus ; 

 first segment 1,3 mm. long and 6,5-times as long as thick at distal extremity, second 0,24 mm. 

 long, third 0,2 mm., fourth 0,24 mm., fifth 0,42 mm., the first segment being a little longer 

 than the sum of the following, the proportion being as i : 0,85. Chela 0,81 mm. long, about 

 twice as long as the fifth segment; fingers one-third longer than the palm. 



Relative dimensions of third legs: merus 1,4; carpus i; propodus 1,16. Merus 6-times 

 longer than wide, armed, as in the genus Parabetaeus, with i or 2 small spinules on the 

 proximal half of the posterior margin, ischium also with a movable spine near the base ; carpus 

 slender, 7-times as long as thick at distal extremity ; propodus 9-times as long as broad, with 

 5 spinules on the posterior margin, of which the spinule at the distal extremity is the longest 

 of all, 0,34 mm. long, almost half as long as the dactylus; there are also 3 or 4 spinules at 

 the distal extremity of the anterior margin, preceded by 2 or 3 smaller ones. Dactylus measuring 

 two-fifths of the propodus and one-third of the merus, slender, 6, 6-times as long as thick at 

 the base, slightly curved, simple, with 2 or 3 setae at the distal third of the anterior margin. 

 These legs are slightly setose, especially the propodus. 



Eggs ovoid, 0,65 mm. long, one and a half as long as thick. 



Length 18,5 mm. 



Synalpheus Sp. Bate. 



The Russian naturalist Paulson has been the first who recognized in 1875 the generic 

 value of the genera Alphetis and Synalpheus when he observed the fact that in the latter genus 

 the epipods of the thoracic legs are wanting. Erroneously, however, Paulson created the new 

 genus Alpheoides for those species which are furnished with epipods, while he left the name 

 of Alpheiis to those that are destitute of these appendages. Ignorant of Paulson's paper I also 

 recognized, thirteen years later, the close relationship of the species which are at present included 

 in the genus Synalpheus: for the first time, indeed, the old genus Alpheus Fabr. was divided 

 by me into four natural groups, one of which, the Spinifrons group, corresponds to the present 

 genus Synalpheus (J. G. de Man, in: Archiv f. Naturg. 53. Jahrg. 1888, p. 498). In the same 



53 



