14 
THE VOYAGE OF H.M.S. CHALLENGER. 
several of the spines of the dactyl are also very long ; the second to fourth ambulatory 
legs, which have been already described, are devoid of spines, except a series of spinules 
on the anterior margin of the merus and posterior margin of the dactylus of the second 
pair and a spinule at the distal ends of the merus-joints of all the legs ; the anterior 
surface of the merus of the third leg is granulated. Colour (in spirit) yellowish, inclining 
to red in some places, as, for instance, on the gastric region of the carapace. 
Adult $. 
Length of carapace to base of rostrum, 
Breadth of carapace, . 
Length of chelipede, . 
Length of first ambulatory leg, 
Length of second ambulatory leg, 
Lines. Millims. 
151 
33 
17 
36 
18 
38 
57 
121 
70 
148 
The unique example (an adult female) was dredged north of the Admiralty Islands, 
lat. 1° 54' 0" S., long. 146° 39' 40" E., in 150 fathoms (Station 219). 
It is one of the finest of the Brachyura dredged in the Challenger Expedition, and it 
is therefore very appropriately associated with the name of the late Director of the 
Civilian Scientific Staff of the Expedition. 
Cyrtomaici, n. gen. 
M 
Carapace transverse and very convex, broadly rounded on the sides of the branchial 
regions ; spinose ; the spines of the gastric region greatly developed. Spines of rostrum 
short, not contiguous. Epistoma transverse. Post-abdominal segments (in the male) 
distinct. Eyes rather long, slender, or rather robust, with a spinule at the distal 
extremity. Antennas long, the basal joint slender, in contact with the front at the 
distal extremity. Outer maxillipedes with the merus and ischium-joints strongly 
spinulose, the merus narrower than the ischium, longer than broad, and sub truncated at 
the distal extremity, with its antero-external angle produced, spiniferous ; the next joint 
articulated with it at its antero-external angle ; exognath slender. Chelipedes (in the 
male) very slender and spinulose, the palm not at all dilated, the fingers slender, nearly 
straight, and meeting along their inner margins when closed. Ambulatory legs very 
long and slender, with the joints more or less spinulose, the dactyli long, slender, and 
nearly straight. 
This genus is distinguished from all others of the same section of the family by the 
remarkable convexity of the carapace, which is- almost vertically deflexed at the gastric 
region, and the great development of its gastric spines, and by the elongated and slender 
spinuliferous chelipedes. 
