32 



as the i st , which is only a trifle shorter than the chela. The relative measurements of the 

 legs of the 3 rd pair (Fig. 15b) are the following : merus 2,37, carpus 1, propodus 1,45, dactylus- 

 0,25 (measured from the proximal extremity of the anterior margin to the tip of the ventral hook). 

 Merus 3,33-times as long as wide, carpus 2,8-times as long as thick at distal extremity, pro- 

 podus 4,4-times as long as broad, lower margin with 7 short spinules, long 0,07 — 0,08 mm.,, 

 besides the two at the far end, dactylus 1 ,9-times as long as broad at base ; the ventral hook 

 is placed perpendicular (Fig. 15^) to the posterior margin of the dactylus and appears- 

 twice as long as broad at its base, the dorsal hook is almost one and a half as long as the 

 other and appears at its base also broader than the ventral hook, while the notch between- 

 both is concave. Merus 1,64-times as long as the propodus. 



Ova 0,7 mm. long. Entire length about 1 1 mm. 



Syn. biunguiculatus (Stimps.) Cout. of Djibouti and of the Maldive Archipelago is very 

 closely related, but apparently differs from the described female not only by the posterior 

 margin of the telson being a little more prominent, but especially by the much 

 smaller size of the dorso-lateral spinules: according to Coutière's figure 8d the 

 distance between the implantation of the anterior pair and the posterior margin appears ten 

 times, but in the female from Stat. 144 only five times as long as the spinules. The measure- 

 ments of the 3 rd legs nearly agree, but the propodus appears a little less slender than in 

 Coutière's figure Sc: the proportion between the length and the width of the propodus in 

 Coutière's species was erroneously indicated by me (1. c. 191 1 (text) p. 275, Table B, N° 5} 

 as being four times, it is indeed five times. 



Syn. pachymeris Cout. apparently differs by the shape of the lateral frontal teeth that 

 are broader and more obtuse, by the 3 rd antennular article being distinctly shorter than the 

 2 nd , by the lamella of the scaphocerite being shorter than the latter and by the absence of 

 the 3 to 6 movable spinules, with which the lower margin of the merus of the 3 rd legs is 

 armed, though, according to Coutière, these spinules are sometimes wanting in this species 

 owing either to their fragility or because they should be not developed at all. 



As regards, finally, the species from the Indian Archipelago which was referred by me 

 (1. c. p. 273) to Syn. biunguiculatus, it seems to me very probable that it is identical with the 

 species from Stat. 144, the telson presenting exactly the same form and characters, but the 

 3 vd antennular article is described as one-fourth shorter than the 2 nd and the rostrum as. 

 reaching to the middle of the visible part of basal antennular article and as being a little more 

 slender. In Table A, p. 274, the proportion between the length of the telson and the width. 

 of the posterior margin of N u 2 is not 3,3, but 3,17. 



23. Alpheus Hailstonei Cout. var. laetabilis de Man. 



Alphens Hailstonei Cout. var. laetabilis J. G. de Man, Siboga Exp., Monogr. XXXIX d 1 ,. 

 Part II, Family Alpheidae, 191 1 (text) p. 333, 1915 (plates). PI. XIV, fig. 64^, 64e. 



Stat. 99. June 28/29/30, 6°f.$ N., i20°26'E. Anchorage off North-Ubian. 16—23 m - Litho- 



thamnion-bottom. 1 female without eggs. 

 Stat. 144. August 7/9. Anchorage north of Salomakiëe-(Damar)-island. 45 m. Coral bottom. 



and Lithothamnion. 2 females without e^gs. 



00 



