OF THE COASTS OF SOUTH AMERICA. 41 
From the characters of the feet, and the form of the body, as well as some other charac- 
ters, it might probably be placed between Camposcia and Inachus, without any consider- 
able violation of its affinities. There are, however, some indications about the structure 
of the external pedipalps, and the form of the abdomen, especially of the female, which 
would seem to intimate some not very obscure relations to a group remote from those 
genera. 
MicroruHYNCHUS GIBBOSUS. 
Tab. VIII. Fig. 1. 
Micr. testd gibbosd, rostro bifido. 
Hab. ad Insulas Gallapagos dictas. 
3 Mus. Soc. Zool. 
The carapax is broadly pyriform, gibbous, rounded ; the regions elevated, and sepa- 
rated by rather deep furrows; the surface covered, particularly on each branchial 
region, with numerous distinct rounded tubercles resembling very minute pearls. The 
rostrum is very small and bifid. The orbits are wide, and have a hollow at the outer 
side for the lodgment of the eyes when at rest, though not deep enough to conceal 
them entirely. A small fissure divides the upper margin of the orbit from the rostrum, 
and another externally from the tooth of its outer angle. The eyes are larger'than 
their peduncles. . 
The external untenne are half as long as the body, the basilar joint as long as the ros- 
trum, with a tooth at the outer angle. The internal antenne are lodged in a single cavity, 
open in front, bounded above by the rostrum, and on each side by the basilar joint of 
the external antenne. The pedipalps resemble those of Camposcia, excepting that the 
second joint of the inner footstalk is more heart-shaped, and deeply notched for the at- 
tachment of the moveable palp, which is long and greatly developed. 
The abdomen of the male (the only sex yet observed) has seven joints, each of which 
has an elevation in the centre: the first, which is wholly apparent when the animal is 
viewed from above, is somewhat quadrate, with a small tubercular tooth in the centre ; 
the second very short ; the third much broader than the rest, and the remainder ab- 
ruptly narrower. 
The first pair of legs are thicker than, but not much more than half as long as, the 
others; the surface granulated ; the hand rounded, and terminated byarched fingers which 
meet only at the apew, where they are denticulated. The four posterior pairs of legs are 
on the average nearly twice the length of the body, diminishing in the order 3.4.2.5. 
They are cylindrical and hairy ; and the nails are long, slender, and but slightly arched. 
The general colour of the specimen is yellowish white. 
Length of the carapax 6 lines ; breadth 5 lines. 
One specimen only, a male, was obtained by Mr. Cuming at the Gallapagos Islands, 
in sandy mud at six fathoms depth. 
VOL. II. G 
