South African Crustacea. 23 



pointed apex having at the base a pair of articulated spines, 

 above which are three pairs of minute marginal spines, incon- 

 spicuous among the plumose marginal setae. 



The first joint of the first antennae has a leaf-like appendage 

 at the base, the second and third joints successively shorter, 

 but both rather long, the flagella longer than the peduncle, 

 the shorter one (in the male) being at the base the wider and 

 at a little distance from the base expanding and then abruptly 

 narrowing so as to become less wide than its longer com- 

 panion. In the second antennae the apical tooth of the scale 

 does not quite reach the top of the setose distal margin. 



The characters of the maxillae and maxillipeds are well 

 shown by Dr. Balss ; those of the lower lip and one mandible 

 are seen in the present plate ; the other mandible appears 

 to have the molar process rather less strongly developed. 



The first three peraeopods are, as usual in this family, 

 similar in structure, but their difference in size is here very 

 striking, the first pair being very short and the third very 

 long ; the first pair differs from the others in having the 

 apparatus of little brushes of spines, serrate on both edges, 

 situate near the base of the hand and distal end of the wrist. 

 The figures sufficiently show the characters of the exopod and 

 epipod attached to this pair. The fourth pair is considerably 

 shorter than the fifth, and is sometimes difficult to observe 

 from its tendency to fold inwards. The thelycum of the female 

 has been figured and described by Dr. Balss. 



The petasma of the male appears to be exceptional by the 

 long terminal stilets, to which the generic name alludes. 

 These appendages are very similar to the male organs of some 

 Isopoda, formed by adaptation of the inner branch of the 

 second pleopods. In the present species the second pleopods 

 have the inner ramus represented by two little folded plates 

 with a diminutive terminal flagellum of seven joints. A 

 female specimen, 67 mm. in length, had a carapace just over 

 19 mm. long, of which the rostrum took barely 7 mm. ; the 

 fifth pleon segment was 5'5 mm. long, the sixth 12 mm., the 

 telson 8 mm., the uropods 11 mm., the third peraeopods 

 25 mm., the fifth 20 mm. In the somewhat smaller male 

 specimen from which the figures were drawn, the third 

 peraeopods measured 18 mm. and the fifth 15 mm. 



Locality. Flesh Point N. | W. 2 miles (Mossel Bay, Cape 

 Colony) ; depth 15 fathoms. A 1206. 



