REPORT ON THE BRACHYURA. 
75 
tubercles exist on the sides of the branchial regions, above the bases of the ambulatory 
legs, and there is an oblique series of small tubercles on each pterygostomian region. 
The prseocular spine is well developed. The rostrum (in the adult) is about one-fourth 
the length of the carapace, and is cleft through half its length, with the spines slightly 
divergent. The orbits are widely open above and deeply fissured below ; the inferior 
fissure rather narrower than in the preceding species. The sternum and post-abdomen 
are nearly as in Libinia smithii. The basal antennal joint, as in that species, bears two 
spines, one on the outer margin, and one at the antero-external angle ; the outer 
maxillipedes also are nearly as in Libinia smithii. The chelipedes (in the adult) are 
moderately elongated, rather less than two and a half times the length of the body, with 
the joints closely granulated, but not tuberculated; the merus-joint is subcylindrical; the 
carpus has two obscure ridges on its outer surface ; the palm is rather shorter than the 
merus, slightly compressed, but not carinated; the fingers more than half the length of the 
palm and denticulated on their inner margins. The ambulatory legs decrease successively 
in length from the first to the last, the first are more than three times the length of the 
carapace, the joints in all are subcylindrical and granulated, the dactyli slightly arcuated 
and shorter than the penultimate joints. Colour (in spirit) yellowish-brown; the carapace 
is rather thinly pubescent. 
Adult <$ . 
Lines. 
Millims. 
Length and breadth of carapace, about 
17 
36 
Length of rostrum, about .... 
5 
11 
Length of a ehelipede, .... 
391 
83-5 
Length of first ambulatory leg, 
53 
112-5 
An adult and two smaller males and three small females were dredged off the coast of 
Chiloe in 45 fathoms, in lat. 46° 53' 15" S., long. 75° 12 ' 0" W. (Station 304). 
In the younger specimens the tubercles of the carapace are less numerous ; the 
cardiac and intestinal spine, and one (the lateral) branchial spine are always strongly 
developed. 
Perhaps the nearest ally to this species is Libinia coccinea, Dana, 1 from the East 
Patagonian coast, 30 fathoms, from which the Challenger species is distinguished by the 
much more deeply-cleft rostrum, the existence of well-developed spines on the cardiac 
region and posterior margin of the carapace, and the longer lateral branchial spines ; 
characters which are constant both in the young and adult. The typical species, Libinia 
granaria, Milne Edwards and Lucas, is distinguished by the peculiar tooth of the distal 
margin of the merus-joint of the exterior maxillipedes. 
Libinia spinosa, Milne Edwards, which has been recorded from Brazil, Patagonia, 
and the coast of Chili, is apparently distinguished by the much more numerous spines of 
the carapace and the spinose post-abdomen of the male. 
1 Libidocea coccinea, Dana, U.S. Explor. Expect, vol. xiii., Crust, i. p. 88, pi. i. fig. 3, 1853. 
