100 



ALPHEUS HAILSTONE!. 



larger chela in adult individuals broader (or higher) than 

 in the typical species, the proportion between length and 

 breadth being in the adult male 2,58, in the adult female 

 2,76, in the typical species, however, 3,33. 



Propodites of 3 rd legs, in adult individuals, but one 

 fourth longer than the carpopodites ; dactyli without acces- 

 sory claw on the posterior margin, but with a tooth on 

 the anterior, lying close to it, as in the var. laetabilis, 

 which tooth probably also occurs in the typical species, 

 as it may easily be overlooked. 



Length 19 mm. 



3. Alpheus facetus, n. sp. 



Station 273. Anchorage off Pulu Jedan, East coast 

 of Aru-islands (Pearl-banks). Depth 13 M. 



A new species of the group „macrochirus" Cout., closely 

 related to A. gracilis Heller and A. splendidus Cout. 



Rostrum acute, projecting straight foreward, as long as 

 l 3t joint of antennular peduncle, narrow, rostral carina not 

 compressed, obtuse, prominent and reaching almost to the 

 middle of the carapace. Orbital spines acute, much shorter 

 than the rostrum, arising from the anterior margin of 

 the orbital hoods, not, as in A. splendidus, from their 

 upper surface. Telson one and a half as long as broad, 

 its posterior margin without dentiform prominence. Movable 

 spine at the postero-lateral angle of the exopodite of caudal 

 fan black. 



Second joint of antennular peduncle a little shorter than 

 the visible part of the 1 st , 3 rd joint one sixth shorter than 

 2 nd ; stylocerite reaching to the middle of 2 nd joint. Carpo- 

 cerite longer than the antennular peduncle, stout ; spine of 

 basicerite almost as long as 1 st joint of the antennular 

 peduncle. 



Larger chela almost 3-times as long as high, fingers 

 two fifths of the palm, lower border entire, rounded, upper 

 border with a longitudinal groove, bounded by two ridges. 



Notes from the Leyden Museum, Vol. XXX. 



