Crustacean Fauna of South Africa. 265 
nently projecting lobe, 6th equal to 4th and 5th together, elongate- 
oval, palm distinguished from inferior margin only by 2 spines and 
by its minute denticulation, inferior margin with 3 spines and several 
setae, finger evenly curved, equal to palm; in ? shorter, 5th joint 
stouter, inferior margin of 6th with only 1 spine at junction with 
palm, otherwise as in ¢. 
Second gnathopod, in ¢ elongate, 2nd joint curved, 3rd lobed on 
anterior margin, 4th not or scarcely apically produced as in I. anguipes, 
5th with a narrow lobe projecting backwards below 4th, 6th elongate, 
34 times as long as broad, curved, inferior concave margin nearly 
parallel with upper convex margin and bearing long setae, a broad, 
truncate, apically bifid and denticulate tooth near the hinge, finger 
curved, not quite reaching base of 6th, inner margin near the hinge 
with 2 semicircular excavations to receive the bifid tooth on the palm; 
in the immature Jf the hand is not so long, inferior margin straight, 
not convex, 2 teeth instead of one apically bifid near the hinge, finger 
not doubly excavate; in ? similar to lst gnathopod and not larger. 
First and second peraeopods as in I. anguipes. 
Third to fifth peraeopods not slender, 2nd joint expanded, hind 
margin most convex in 5th peraeopod, postero-inferior angles rounded. 
First and second uropods, outer ramus shorter than inner, rami 
shorter than peduncle in Ist uropod, inner ramus subequal to peduncle 
in 2nd uropod, apex of peduncle of 1st with acute spine. 
Third uropod reaching very little beyond end of 2nd uropod, rami 
very small, equal to apical width of peduncle, inner ramus narrow, 
outer broad at base, distal half suddenly contracted, apex minutely 
hooked, 3 denticles on upper margin. 
Length: 3mm., ga trifle over 3 mm. 
Colour: G usually whitish with a broad dorsal stripe of claret, 
? usually greyish or claret, pleon sometimes lighter or with irregular 
patches of black, whole body, side-plates and appendages with minute 
circular black pigment specks, but the two types of coloration are not 
confined to the respective sexes. 
Locality : Buffel’s Bay (False Bay). 28/9/15 and 1/3/15. (K.H.B.) 
64 and ovigerous 2? ?; Sea Point, near Cape Town. 26/2/14. 
(K.H.B.) 1 ovigerous 9. (S.A.M. Nos. A2533, A3290, and A2922. 
Geogr. Distribution: Widely distributed in the North Atlantic 
(incl. Arctic Ocean) and adjoining seas. 
The chief differences between these specimens and the typical form 
le in the shorter and more rounded telson, which is somewhat similar 
to that of I. commensalis Chevreux, and in the 2nd gnathopod of the 
male. 
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