REPORT ON THE BRACHYURA. 
219 
differ little from the females in the series I have examined. They sometimes, but not 
invariably, have larger and more robust chelipedes . 1 
Cardiosoma, Latreille. 
Cardiosoma, Latreille ( Ccirdisoma ), Encycl. Meth. Hist. Nat., vol. x. p. 685, 1825. 
„ Milne Edwards, Hist. Nat. Crust., vol. ii. p. 22, 1837; Ann. d. Sci. Nat., ser. 3, 
Zool. xx. p. 203, 1853. 
„ S. -J. Smith ( Garcliosoma ), Trans. Connect. Acad., vol. ii. p. 142, 1870. 
Carapace transverse, elevated, and sometimes very convex anteriorly ; with the 
branchial regions antero- laterally convex, and very greatly developed, as in Geocarcinus. 
The antero-lateral margins are sometime's armed with a small tooth placed at a short 
distance from that at the exterior angle of the orbit. Front deflexed, and usually broader 
than in Geocarcinus ; it nearly reaches the anterior margin of the buccal cavity, and 
conceals, in part, the antennules. Orbits large and widely open, with the margins entire ; 
the interior subocular lobe is separated by a wide hiatus from the frontal margin, and 
this hiatus is occupied by the antennae. Endostome without distinct longitudinal ridges. 
Post-abdomen (in the male) distinctly seven-jointed. Eye-peduncles of moderate size 
and thickness ; they do not nearly fill the orbital cavities. The basal joint of the 
antennae is short and somewhat dilated, and does not usually quite reach the frontal 
margin; the flagellum is very short. The exterior maxillipedes do not meet along their 
inner margins, but enclose a lozenge-shaped interspace; the ischium and merus-joints of 
the endognathi are rather broad and truncated, the merus even rather concave at the 
distal extremity; the carpaljoint is articulated with the merus at its antero-external angle. 
The chelipedes are usually unequal, and the larger one sometimes ( Cardiosoma guanhumi ) 
enormously developed ; merus more or less trigonous ; carpus usually with a spine on its 
interior margin ; palm often shorter than the fingers, which, as usual, are more or less dis- 
tinctly dentated on the inner margins. Ambulatory legs robust, and more or less elongated; 
the merus-joints with the superior margins acute, and armed with a subterminal spine; 
dactyli as in Geocarcinus, armed with spinules ranged in longitudinal series. 
The species of this genus which, like Geocarcinus, are terrestrial or subterrestrial, are 
not numerous, and their discrimination is often difficult . 2 
One, Cardiosoma carnifex (Herbst)= % Cardiosoma obesum, Dana, Cardiosoma 
1 The types of these species were from the Australasian seas, whence also there is a good series of specimens in the 
British Museum collection, obtained during the voyage of H.M.SS. “Erebus” and “ Terror”; the Museum also possesses- 
a specimen designated as from the Cape of Good Hope, and another from the West African Coast (Fraser). With these 
specimens the Challenger examples apparently agree in all particulars. In adult specimens of large size the branchial 
regions are very considerably dilated, and the granulated line which defines their antero-lateral margins is partially or 
even entirely obsolete. In the smallest examples this line is very distinct, but the lateral series of spinules on the dactyli 
of the ambulatory legs is not developed, and they are therefore armed with only four (marginal) series of spinules. 
2 Several of the species here placed provisionally as synonymous with Cardiosoma, carnifex, are regarded by M. de 
Man ( Notes Leyden Mus., ii. pp. 31-36, 1879) as distinct species, but A. Milne Edwards is inclined upon the whole to 
doubt their specific distinctness ( Nouv . Archiv. Mus. Hist. Nat., vol. ix. p. 264, 1873). 
