52 
females among our specimens have the palms of the chelipeds 
less inflated than those of the males, and with a less decided 
cavity between the bases of the closed thumb and finger, but 
there is little difference in hairiness. In both sexes the plumose 
sete feather the long fingers of the walking legs almost to their 
tips. 
The narrow, strongly-bent pleon of the male has a transverse 
setigerous ridge on the second and third segments. The fourth 
is wider at the base than the third, then narrows to the fifth, 
which is shorter than the tapering rounded-ended sixth. 
A female, laden with eggs, has a carapace 9mm. long by 
8mm. broad. In the largest male the carapace measured 
8mm. in length with a breadth of 7mm. The length and 
breadth of H. orbiculare is given by Desmarest as about an inch. 
Krauss describes the specimens from Table Bay as 8°7 lines long 
by 7°4 broad. 
Locahty.—False Bay, Roman Rock, N.W.2N., } mile; 
depth, 18 fathoms ; bottom, sand and shells. 
OXYSTOMATA. 
References have already been given in earlier parts of these 
investigations to the discussion of this tribe by Alcock in 1896. 
In 1898 Ortmann adopts Alcock’s classification (Bronn’s 
Thierreich, Vol. V., Part. 2, Lieferung 52 p. 1156. In 1900 
Miss Rathbun gives the following definition :— 
‘“Carapace with the antero-lateral margins arcuate or orbi- 
culate ; sometimes subglobose or more or less oblong, with 
sub-parallel margins. Epistome much reduced. Buccal frame 
more or less triangular, produced and narrowed forward. with 
the margins anteriorly convergent. Six to nine pairs of 
branchiae. Efferent channels opening at the middle of the 
endostome, which is produced forwards. The afferent channels 
open either behind the pterygostomian regions and in front of 
the chelipeds, or at the anterolateral angles of the palate. First 
antennae folded longitudinally or obliquely. The genital 
organs of the male are exserted, either from the bases of the 
fifth pair of legs, or from the surface of the sternal plastron.” 
(The American Naturalist, Vol. XX XIV., No. 402, p. 515.) 
The families included are the Calappidae, Matutidae, Leuco- 
siidae, and Dorippidae, the first three having the “ legs normal 
in size and position,” whereas the Dorippidae exhibit the “last 
two pairs of legs much reduced in size, and having a peculiar 
position in the dorsal plane of the body.” 
