1904.] ASELLOTA-GROUP OF CBUSTA.CEANS. 327 



lias a difterent shape ; it is slightly more than twice as long as 

 deep, conspicuously deeper at a shorter distance fi'om the base 

 than at the distal end ; the upper margin is less convex than in 

 /S. occidentale, Avhile the lower margin is considerably convex in 

 its proximal and concave in its distal half ; the distal process is 

 longer but much narrower than in S. occidentale, bifurcate at 

 the end and sometimes with a feeble tooth on its postei'ior margin ; 

 distribution of hairs as in the species mentioned. The "claw," 

 formed by the seventh joint and the claw itself, slightly longer than 

 in yiS'. occidentale and more haiiy at the lower margin. — In the 

 young — probably also in the adult — female the hand differs some- 

 what in shape from those of the tyi^o preceding species : as in 

 >S'. occidentals it is a little more than half as long again as broad,, 

 but the lower margin is comparatively longer, measured to the 

 base of the lower saw-tooth of the palmar edge slightly more than 

 half as long as the upper margin, and the angle between the 

 lower margin and the palmar edge is less than 100° ; the notch at 

 the distal end of the lower margin is longer than in aS'. occidentale. 



Abdominal shield is slightly longer than broad, otherwise as in 

 •S'. occidentale. 



Uropoda seem to be only a little more than half as long as the 

 abdominal shield ; the rami — preserved only in the young 

 female — a little shorter than in *S'. occidentale. 



Length of the largest male 4*5 mm. 



Occurrence. West Indies. Two adult males and a young female 

 were found oil corals presented to the Zoological Museum in 

 Copenhagen by Mr. G. A. Hagemann. The corals were said to 

 be from " deep water," which probably signifies about 100 fathoms. 



Remarks. It is certain that S. occidentale and ^S'. antillense are 

 valid species ; having seen no specimens of 8. stehhingii it has 

 been necessary to rely on Miss Richardson's drawings, and I 

 believe that neither of my species is identical with this form from 

 Bermudas. It may be added that the hand of the first legs in the 

 male is similar to that of the second legs in species of Ischyrocerus, 

 a genus of Amphipoda; furthermore that the hand of the female in 

 Stenetrium is similar to that of the second legs in species of Metopa, 

 another genus of Amphipoda, and in the latter genus specific 

 differences similar to those pointed out in females of Stenetrium, 

 are well known. 



9. Stenetrium siAMENSE, sp. n. Male and not quite full-grown 

 female. (Plate XXI. figs. 2 «-2 i.) 



Body narrower than in the preceding forms, slightly more than 

 four times as long as broad. 



Head has its upper surface (the frontal plate excepted) half 

 as broad again as long ; the lateral part is not expanded, with the 

 front portion of the lateral margins converging and the angle 

 not produced, obtuse ; front margin outside the base of each 

 antennula produced into a broad short triangle with the apex 

 rounded. Eyes small, i-ounded, placed near the lateral margin. 



