318 
THE VOYAGE OF H.M.S. CHALLENGER. 
attaining the apex of the merus of the endognath. The chelipedes (in the adult) are 
robust and somewhat elongated; with the joints granulated but not carinated or toothed; 
merus (in the adult male) subcylindrical and nearly as long as the carapace ; carpus a 
little shorter than the palm, which is more than half the length of the merus ; fingers 
nearly as long as the palm, compressed, finely granulated, and scarcely toothed on the 
inner margins. Ambulatory legs slender and moderately elongated, with the dactyli 
styliform, hairy on the superior margins, and shorter than the penultimate joints. 
Colour (in spirit) light yellowish-brown. 
Adult $ . 
Lines. 
Millims. 
Length and breadth of carapace, about 
121 
26 
Length of a chelipede, ..... 
24 
51 
Length of first ambulatory leg, about . 
16 
33-5 
Off Nukalofa, Tongatabu, 240 fathoms (Station 172a), an adult male ; Fiji Islands, 
lat. 20° 56' 0" S., long. 175° 11' 0" W., 315 fathoms (Station 173), an adult female 
and three smaller males. 
In the small males the terminal post-abdominal segment is as distinctly granulated as 
the others. 
Lithadia, Bell. 
Litliadia , Bell, Trans. Linn. Soc. Lond. (Zool.), vol. xxi. p. 305, 1855. 
Of this genus I have examined but three specimens, referable to two species, Lithadia 
cariosa, Stimpson, var. and Lithadia (?) sculpta, Haswell, and I am unable, from the 
descriptions only, to indicate any constant characters by which it may be distinguished 
from Ehalia, except such as are derived from the carapace, which is very strongly 
granulated and more or less pitted, sulcated, and eroded on the dorsal surface, as in the 
genera Oreophorus and Spelasophorus ; but in these genera the carapace is dilated at the 
postero-lateral margins, and more or less produced over the bases of the ambulatory legs. 
From Actasomorpha, Miers (perhaps = Osachila, Stimpson), it is distinguished by the 
form of the carapace, which in the typical species of Actasomorpha (Actasomorpha erosa) 
is cancroid in shape, with the antero-lateral margins regularly arcuated. 
The following is, I believe, a complete list of the described species of this genus : — 
TAthadia cumingii, Bell. Central America; Puerto Portrero (13 fathoms). . 
Lithadia cariosa, Stimpson. North Carolina, southward to Florida, Bahia (”?). 
Lithadia cadaverosa, Stimpson. West of Tortugas ; Couch Beef (to 40 fathoms). 
Lithadia pontifera, Stimpson. Barbados. 
IAthadia cuhensis, von Martens. Cuba. 
Lithadia hrasiliensis, von Martens. Brazil, Bio de Janeiro. 
