Crustacean Fauna of South Africa. 267 
near hinge a setiferous bifid tooth, of which the lower tooth is longer 
and more pointed, whole inferior margin with a row of plumose setae, 
. finger curved, with 2 sight emarginations at base of inner margin; in 
young ¢ ¢ 2°5 mm. long, the inferior margin is without a “ step,” 
and in those 3 mm. long it has only a slight ‘ step”. 
First and second gnathopods in ? similar to one another and very 
like those of I. anguipes, but 6th joint narrow-oval with 2 spines 
defining the palm. 
Peraeopods very similar to those of I. anguipes, 3rd—5th rather 
robust, 2nd joint expanded, ovoid, hind-margin most convex in 5th 
peraeopod, postero-inferior angles rounded. 
First and second uropods, outer ramus shorter than inner, peduncle 
of Ist with acute apical spine. 
Third uropod reaching as far as or a little beyond ends of Ist and 
2nd, peduncle with 3 spines on upper margin, outer ramus } length of 
peduncle, inner ramus shorter than outer, both narrow, outer with an 
apical recurved spine and 2 minute denticles. 
Length: & 4mm., nonovigerous ? 3 mm. 
Colour : Mottled greyish, head and peraeon segments 1, 3, 4 and 5 
darker than rest of body, black pigment specks absent. 
Locality ; Sea Point, near Cape Town. 5/10/14. (K.H.B.) 1 im- 
mature ¢, low-tide; Swakopmund, German S8.W. Africa. May, 1908. 
(J. Drury.) 3 ¢¢, 5 immature ¢ 4, 4 nonovigerous 9? 2, from 
floating buoy; Cape Town. 19/8/98. 1 ¢ off a Palinuwrus lalandii. 
(S.A.M. Nos. A2926, A2953, and A3393.) 
ISAEOPSIS n. g. 
Side-plate 5 as deep as 4 and much deeper than 6, entire. First 
antenna shorter than 2nd, accessory flagellum distinct, 1-jomted. Palp 
of maxilliped 4-jointed. First and second gnathopods in 2 subequal, 
second gnathopod in ¢ very large. All the peraeopods stout and 
subchelate. 
The resemblance to Isaea M. Edw. in general habit and the sub- 
chelate peraeopods is very remarkable, but the uncinate 3rd uropods, the 
mandibular palp, and the 2nd gnathopod of the male would seem to 
necessitate placing this genus in the family Jassidae. The subchelate 
peraeopods are evidently an adaptation to the habitat of the animal. 
IsAEOPSIS TENAX 0. sp. 
(Plate XXVIII. Figs. 19-21.) 
Lateral lobes of head not very prominent, subacute. Eyes small but 
