357 



broad). The outer posterior margin is glabrous, but the inner is fringed with about 20 

 setiform spines which are shorter than usually : according to Coutière's description they should 

 be 0,3 mm. long, while the longest in the specimen, collected by the "Siboga", near the sub- 

 apical spine, measure 0,1 8 mm. The external posterior margin of the carpus, which is 0,86 mm. 

 long from articulation to articnlation, ends distally in a subacute tooth and it carries five long 

 setae and just beyond the middle a very small spinule, that is 0,04 mm. long; the internal 

 posterior margin is fringed with 10 or 11 setiform spinules, which are longer than those of 

 the merus. Propodus one and a half as long as the carpus, with 7 spines on the posterior 

 margin and a much smaller spine at the far end of the anterior border; the long setae of the 

 posterior margin are not perpendicular to the joint, but are directed obliquely towards the 

 dactylus, the accessory claw of which is small. 



General distribution: Maldive Archipelago (Coutière) ; Cheval Paar, Ceylon 

 (Pearson). 



20. Alpheus crinitus Dana. 



Alpkeus crinitus J. D. Dana, U. S. Explor. Exped. Crustacea. p. 548. PI. 34. fig. 8. 

 Alpheus crinitus A. Ortmann, in: Zoolog. Jahrb. V. Abth. f. Syst. 1890. p. 479. 



Thanks to the courtesy of Prof. Döderlein of Strassburg I was enabled to examine the 

 specimen from Samoa, that was referred by Dr. Ortmann to A. crinitus Dana : also in my 

 opinion this specimen, which is a male, 23 mm. long and apparently adult, appertains to Dana's 

 species. The rostrum is as long as the i st antennular article, rostral carina compressed, obtuse, 

 not extending beyond the base of the orbital hoóds from which it is separated by deep grooves. 

 Frontal margin slightly emarginate at either side of the rostrum. Second antennular article 

 hardly twice as long as the visible part of the i st , 3 rd article hardly shorter than that visible 

 part; stylocerite acuminate, a little longer than basal article. Lower spine of basicerite small. 

 Carpocerite about as long as the antennular peduncle, not shorter; terminal spine of scaphocerite 

 a little longer than the antennular peduncle, the lamina as long as that peduncle. According 

 to Dana the terminal spine of the scaphocerite should be slightly shorter than the peduncles. 



Telson 2,82-times as long as the posterior margin is broad, the latter with the outer 

 angles not at all prominent, obtuse; inner spinules of the posterior margin short, hardly one-third 

 the width of the margin, outer spinules half as long. Proportion between the width at base 

 and that of the posterior margin 1,75. Spinules of the upper surface rather far distant from 

 the lateral margins, situated almost midway between the latter and the m i d - li n e 

 of the telson; the spinules measure one-seventh the length of the telson, the anterior pair 

 is situated before the middle, the proportion between the length of the telson and the distance 

 of that pair from the posterior margin being 1,66 and the proportion between the distances 

 of both pairs from the posterior margin amounts to 1,6. Merus of larger cheliped obtuse at 

 the apex of the upper margin, infero-internal margin terminating in an obtuse tooth. The chela 

 agrees with Dana's description and figures. Smaller cheliped missing. 



The carpal segments of the 2 nd legs are 1,9 mm., 2,14111111., 0,84 mm., 0,9111111. and 



225 



SIISOGA-EXrEDITIE XXXIX a'. 46 



