378 Mr. E. J. Miers on Ocypoda. 
Kingsley mentions the occurrence of O. arenaria on the 
west coast of Mexico (é.c. p. 185) ; 
but I think it possible 
that the specimens from this locality should be referred to 
O. Kuhlit, var. occidentalis, Stimpson. 
In the following 
notes the names in brackets which follow the localities are, 
with few exceptions, the names of the donors (and not neces- 
sarily the collectors) of the specimens in the Museum collection. 
The principal characters separating the species of Ocypoda 
may be briefly tabulated as follows :— 
I. Ocular peduncles prolonged beyond the 
cornea as a spine or style. 
A. The terminal style tipped with a pen- 
cil of hairs.: 
Stridulating-ridge finely striated .... 
B. The terminal style without hairs at 
apex. 
* Fingers of both chelipedes acute. 
Sides of the carapace straight behind 
the rather acute orbital angles. 
Stridulating-ridge coarsely stria- 
ted above, finely striated below. . 
Sides of carapace slightly arcuated 
behind the scarcely acute antero- 
lateral angles. Stridulating-ridge 
finely striated throughout ...... 
Sides of carapace strongly arcuated ; 
antero-lateral angles obsolete. 
Stridulating-ridge developed only 
in its lower portion, and the strize 
separated by very wide intervals. 
Carapace broader, with the sides 
straight behind the acute antero- 
lateral angles. Stridulating-ridge 
narrow, tuberculate throughout. . 
** Fingers of the smaller chelipede 
dilated at the distal extremity. 
Stridulating-ridgeratherbroad, finely 
and evenly striated ......:..... 
*** Fingers of both chelipedes dilated and 
truncated at the distal extremity. 
Stridulating-ridge narrow, tuber- 
culated above, striated below .... 
II. Hyes rounded at the distal extremity, 
not terminating in a spine or style. 
* A stridulating-ridge developed. 
Stridulating-ridge narrow, tubercu- 
lated. Ambulatory legs with the 
penultimate joints dilated and 
compressed, nearly smooth, with 
long marginal hairs............ 
Stridulating-ridge narrow, usually 
tuberculated. Ambulatory legs 
O. cursor (Linn.). 
O. ceratophithalma (Pallas). 
O. egyptiaca, Gersticker. 
O. rotundata, Miers. 
O. platytarsis, M.-Edw. 
O. macrocera, M.-EKdw. 
O. Gaudichaudit, M.-Edw. 
& Lue. 
O. arenaria (Catesby). 
