REPOET ON THE ANOMURA. 35 



abruptly, and the edge of the ridge thus formed is drawn out into three processes which 

 are separated from one another by eroded depressions ; the floor in all the depressions 

 is more coarsely granular than the rest of the carapace. The fronto-orbital border 

 is narrow, less than one-half the width of the carapace ; the frontal region is considerably 

 produced and terminates in three small rounded lobes, of which the median is 

 largest ; the orbital portion of this border is remarkably short, and marked externally 

 by a rounded tooth. The lateral border commences anteriorly in a blunt projection 

 which is separated by a concave depression from the antero-lateral (or orbital) tooth ; for 

 the first half of its course it is irregular owing to its being encroached on by the erosions 

 of the carapace ; posteriorly it exhibits a raised granular line which curves in on the 

 dorsal surface of the carapace so as to leave a portion of the subbranchial or lateral region 

 exposed. 



The eyes are of small size and placed in ill-defined orbits ; the peduncles with a slight 

 range of movement. The antennules are minute, placed underneath the frontal region 

 and completely concealed by tlie antennar peduncles ; their peduncles are hirsute. The 

 antennal peduncle is broad and composed of only three segments, the first (which is free 

 in the other Raninidea) having fused with the trunk ; the second has a strongly developed 

 external prolongation which exceeds the remainder of the peduncle, the terminal segment 

 is of small size ; the flageUum is minute, but stout, and ciliated on both sides. The 

 external maxillipedes have the ischium slightly convex and twice the length of the 

 merus, the latter joint with a longitudinal sulcus on its outer surface and rather more 

 coarsely granular than the ischium ; the terminal joints are wanting in the single speci- 

 men ; the exognath reaches to the end of the ischium and its apex is subacute. The 

 pterygostomial region is moderately convex and separated from the carapace proper by a 

 deep groove which becomes continuous with the line on the postero-lateral border. The 

 thoracic sternum is nowhere very broad, reaching its maximum between the chelipedes 

 and the first pair of ambulatory limbs, becoming linear between the basal joints of the 

 latter, but dilating again between the first and second pairs of ambulatory limbs ; the 

 anterior part with a sulcus on each side, the posterior with a single median groove. 



The chelipedes are well developed, with the surface finely granular; the merus is slightly 

 hollowed out on its inner aspect ; the propodus is remarkably swollen ; the dactylus and 

 immobile finger are slender, exceeding the propodus in length, their opposed edges with 

 numerous teeth ; the apex of the immobile finger is bent over that of the dactylus. The 

 ambulatory limbs are granulated and fringed with long hairs, the propodi of the first three 

 pairs drawn out into several sharp ridge-like processes, the dactyli but faintly granular 

 and uncinate or sickle-shaped (hence the generic name) ; the fourth pair are of small 

 size and flattened from above downwards, with the dactyli less strongly curved. 



The abdominal segments are moderately convex, gradually tapering towards the 

 extremity, and fringed with long hairs ; the apex of the telsou is rounded. The sexual 



