ON THE BRACHYUROUS DECAPODS OF THE CAPE. 57 

Sp. 1. ( ) Antilibinia Smithii, 7. s. 
Descr. Andtilibinia teste margine laterali anticé tridentato, clypeo bifurcato cornubus intus 
pilosis. 
Nors. The shell of this species is without hairs, almost circular, and has the regions in general 
distinct. The clypeus is bifurcated with a tooth on each side of the base. The anterior lateral 
margin of the shell has three teeth, of which the foremost is situated behind the eyes ; the 
second or middle tooth is the greatest, and directed forwards, while the last is little more 
than a tubercle. The digestive region has an eminence marked on each side. The branchial 
region has five or more tubercles on each side. The cardial region has a tubercle in the middle 
behind, and on each side of it there is an oblique portion of the shell scabrose. The horns of 
the clypeus are pilose on the inside. The digits of the chelz have seven or more teeth on the 
inside. The four pair of hind feet have their third joints thick, and are armed with long curved 
claws. This crab resembles the Libinia spinosa of Milne Edwards so closely, that at first sight 
it might be taken for it. 
Sub-genus. AcANTHONYX, Lat. 

Sp. 2. ( ) Acanthonyx dentatus, W. 2. 
Acanthonyx dentatus, Hist. Nat. des Crust. vol. i. p. 343. 
Sp. 3. ( ) Acanthonyx scutellatus, n. s. 

Descr. Acanthonyx fere duplo longior quam latus, orbite angulo externo unidentato, clypeo 
ad basin tuberculis duobus setiferis supra instructo, testee margine laterali bidentato dente 
posteriori minimo apice subsetifero. 
Nore. The shell of this fine species, which is more than an inch long, is shaped like an heraldic 
shield. It is depressed. The two horns of the clypeus are pilose at their apex, and have two 
setiferous tubercles at their base. On each side of these horns, and at the external angle of 
the orbits, there is a triangular tooth also pilose at the apex. The anterior lateral margins of 
the shell are bidentated. The fore teeth on each side are large, triangular, and blunt. From 
their points the sides of the carapace proceed towards the posterior margin, nearly parallel 
to each other, until they arrive at the second tooth, which is rudimentary, and reduced to a 
setiferous tubercle. The posterior margin of the thorax is rounded. 
Fam. MITHRACIDZ&, Mihi. 
Sub-genus. Denaantius, M‘L. 
Cephalothorax subtriangular, with the lateral margins in front dentated, and behind rounded ; 
the clypeus being quadridentate. 
Orbit simple, with globose moveable eyes, thicker than their peduncles. 
Exterior antenne with the basilar joint broad at the base, then narrower and reaching the 
middle of the clypeus ; while the second joint is shorter and obconical. 
Internal antenne with the basilar joint subcylindrical, and the second subtriangular. 
External pedipalpi with the outer palpus falciform, and the inner palpus having its second joint 
with subparallel sides, the third jot sub-quadrate, emarginate at the apex, with the 
tigellus conspicuous, inserted at its inner angle. 
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