Crustacean Fauna of South Africa. 267 



near hinge a setiferous bifid tooth, of which the lower tooth is longer 

 arid more pointed, whole inferior margin with a row of plumose setae, 

 finger curved, with 2 slight 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 1st with acute apical spine. 



Third uropod reaching as far as or a little beyond ends of 1st 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 .- 4 mm., nouovigerous ? 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 S.W. Africa. May, 1908. 

 (J. Drury.) 3 $ <$ , 5 immature $ , 4 nouovigerous ? ? , f rom 

 floating buoy ; Cape Town. 19/8/98. 1 ^ off a Palinurus 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- jointed. Palp 

 of niaxilliped 4- jointed. First and second gnathopods in ? subequal, 

 second gnathopod in <$ very large All the peraeopods stout and 

 subchelate. 



The resemblance to Isaea M. Eclw. in general habit and the sub- 

 chelate peraeopods is very remarkable, but the uncinate 3rd uropods, the 

 inandibular 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. 



ISAEOPSTS TENAX n. sp. 



(Plate XXYI1I. Figs. 19-21.) 

 Lateral lobes of head not vei'y prominent, subacute. Eyes small but 



