54 MR. T. BELL ON THE CRUSTACEA 
Carapax somewhat depressed, rounded, slightly triangular, broader than it is long ; 
the surface with broad elevations, which are highest over the gastric region ; the latero- 
anterior margin with three strong rounded tubercles, and a small spine behind them. 
Rostrum very short, rounded and bifid. Orbits with a small round tubercle over the 
inner canthus, and a small fissure above. 
Exterior antenne with the basilar joint as prominent as the orbitar tubercle, but 
rather less so than the rostrum ; second joint somewhat heart-shaped, furnished with a 
tuft of rather long hair on the inner edge, as is also the remaining portion of the an- 
tenne. Pedipalps with the second joint of the inner footstalk of an irregularly semi-' 
lunar form, much broader than it is long, not cordate as in the other species of the 
genus. 
Abdomen with the seven joints very distinct. 
Anterior legs above covered with tubercles ; the hand quite smooth, with a carina on 
the upper edge. The fingers are much curved, and in contact only at the apex, which 
is scarcely denticulated ; the moveable one has a strong tooth near its base. The pos- 
terior legs are covered on the upper surface with hairs and numerous spines, many of 
which are furnished with two or three distinct hairs at the point. 
The colour above is brown; that of the hands dark plumbeous: it is paler beneath, 
Length of the carapax 1 inch; breadth 1 inch 3 lines. 
Found by Mr. Cuming in considerable abundance under stones at low water. 
This species belongs to the third section of the genus, as divided by Dr. Edwards : 
his Mithraces deprimés. 
Mirarax DENTICULATUS. 
Tab. XI. Fig. 2. 
Mithr. testé profunde sculptd ; margine laterali dentibus quatuor obtusiusculis ; pedipalpis 
articulo secundo caulis interni cordato ; manibus levibus; pedibus posterioribus pilosis, 
spinosissimis. 
Hab. ad Insulas Gallapagos dictas, sub lapidibus. 
Mus. Soc. Zool., Bell. 
A small species resembling in most of its characters the former one, though differing 
sufficiently to be distinguished from it at the first glance. ‘The markings on the carapax, 
though similar in situation, are much more distinctly and deeply incised ; the teeth on 
the lateral margin, though rather obtuse, have not the rounded, tubercular character 
of the same appendages in Mithr. nodosus. The arms and the feet also are more sharply 
spined. But the character which at once distinguishes them, on a closer inspection, is 
the form of the second joint of the inner footstalk of the external pedipalp, which in 
Mithr. nodosus is crescent-shaped, and much broader than it is long ; and in the present 
species is cordate, and as long as it is broad. 
Colour plumbeous, passing into fuscous. 
