REPORT ON THE BRACHYURA. 
289 
As in the genus Mursia , the posterior margin of the carapace bears distinct lobes or 
teeth ; but Mursia is at once distinguished by the form of the merus of the exterior 
maxillipedes, and the strongly developed lateral spine of the carapace. 
Acanthocarpus, Stimpson, 1 is (as its name imports), distinguished by the extra- 
ordinarily developed carpal (or meral) spine of the chelipedes. 
Paracyclois milne-edwardsii, n. sp. (PI. XXI Y. fig. 1). 
The carapace is irregularly orbiculate, convex and broadest at a point situated a little 
in advance of the middle of the lateral margins ; its dorsal surface, except on the intes- 
tinal region, and the postero-lateral parts of the branchial regions, is coarsely granulated 
and covered with low, smooth, rounded tubercles, which diminish in size towards the lateral 
and postero-lateral margins. The median frontal lobe is broadly rounded, with three 
low tubercles on its upper surface, the lateral margins of the carapace sweep round in a 
regular curve to the protuberances of the postero-lateral margins, which bear four 
unequal spines ; the lateral and postero-lateral margins, and the parts of the carapace 
immediately adjoining the three tubercles of the posterior margin, are granulated. The 
pterygostomian regions are smooth. The post-abdomen (in the female) is rather narrow, 
with subparallel sides ; the five -first segments are transverse and short (the second 
segment with two small lateral protuberances), the sixth segment is quadrate, and slightly 
broader than long ; the terminal segment is triangulate, somewhat longer than broad, 
and distally acute. The eye-peduncles are short and thick, and granulated above, the 
cornese occupying a great part of their inferior surface. The quadrate basal joint of the 
antennae lies loosely within the orbital hiatus, the following peduncular joints are slender 
and very short. The exterior maxillipedes have been already described ; their ischium- 
joints are denticulated on the inner margins, and the merus-joints are slightly concave 
on their exterior surface. The chelipedes and ambulatory limbs are nearly as in Calappa , 
e.g., Calappa g alius ; as in that species the merus of the chelipedes has a subdistal 
crest on its outer surface, but this crest is armed with short spines (not dentated as in 
Calappa gallus) ; the merus, in front of this ridge, and the carpus and palm are externally 
granulated, and the carpus and palm also tuberculated, and the palm dentated on its 
upper margin, as in Calappa gallus, but the tubercles and spines are less prominent than 
in that species ; the granules of the lower part of the exterior surface of the palm are 
very numerous and regular. As in specimens of Calappa gallus I have examined, the 
dactyli of the chelipedes are dissimilar ; that of the left chelipede being much more slender 
than the right, and sinuated. The ambulatory legs are compressed, with the carpus-joints 
obscurely bicarinated above, and the carinse (in the two last pairs) granulated ; the merus 
in the fifth pair is denticulated on its inferior margin. Colour (in spirit) yellowish- white. 
1 Bull. Mus. Comp. Zodl., vol. ii. p. 153, 1871. 
(ZOOL. CHALL. EXP. — PART XLIX. — 1886.) 
Ccc 37 
