72 
THE VOYAGE OF H.M.S. CHALLENGER. 
Libinia, Leach. 
Libinia, Leach, Zool. Miscell., vol. ii. p. 129, 1815. 
„ Milne Edwards, Hist. Nat. Crust., vol. i. p. 298, 1834. 
„ Miers, Journ. Linn. Soc. Lond. (Zool.), vol. xiv. p. 662, 1879. 
The carapace is convex, broadly pyriform, or nearly orbiculate, and its dorsal surface 
is covered with numerous tubercles, which are sometimes developed as spines ; the 
prseocular tooth or spine is usually distinct. The rostrum is well developed (sometimes 
rather small), emarginate or bifid at the apex, and so terminating in two teeth or spines. 
The orbits are small, nearly circular, and well defined, with sometimes an open fissure or 
hiatus in the superior and inferior margins. The post-abdomen (in the male) is distinctly 
seven-jointed. The eyes are small and completely retractile. The basal antennal joint 
is moderately enlarged, and is armed with a tooth or spine at the antero-external angle, 
behind which, on the exterior margin, is usually another tooth. The flagellum is not 
concealed by the rostrum. The merus of the exterior maxillipedes is truncated (not 
toothed) at the distal extremity, and its antero-internal angle is emarginate. The 
chelipedes (in the adult males) are well developed ; palm elongated, subcylindrical or 
compressed, but not enlarged ; fingers minutely and evenly denticulated on the inner 
margins, with a small intermarginal hiatus at base. The ambulatory legs are well 
developed, sometimes elongated, with the joints subcylindrical, unarmed ; dactyli nearly 
straight. 
This genus is closely allied on the one hand to Doclea and on the other to Libidoclea, 
Milne Edwards and Lucas. I have proposed elsewhere 1 to restrict the latter genus to 
the single species Libidoclea granaria, Milne Edwards and Lucas, characterised by having 
the merus-joint of the exterior maxillipedes armed with a strong tooth on its distal 
margin, a character never observed in any species either of Libinia or Doclea. 
The following species are referable to the genus Libinia as characterised above : — 
1. Fissures of the upper and lower orbital margins very narrow or closed ; basal 
antennal joint with a tubercle or very short spine at its antero-external angle. 
Libinia emarginata, Leach ( = Libinia canaliculata, Say, and Libinia affinis, 
Randall). East Coast of United States ; West Indies ; West Coast of North 
America. 
Libinia dubia, Milne Edwards (= Libinia distincta, Guer.-Menev. and B. Capello ; 
Libinia injlata. Streets, var. ?). East Coast of United States ; West Indies ; 
West Coast of Africa. 
Libinia rhomboidea, Streets ; “ East Indies.” (The locality is so given by Streets 
whose description nearly applies to Libinia dubia, of which this doubtful 
species is considered a variety by A. Milne Edwards.) 
1 Proc. Zool. Soc. Lond., p. 28, 1879. 
