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THE VOYAGE OF H.M.S. CHALLENGER.. 
2. Antennal flagellum excluded from the orbital hiatus by a process of the basal 
antennal joint. 
Genera: — Cronius, Stimpson ; Goniosoma, A. Milne Edwards ( — Ocecmus , de 
Haan ; Charybdis, de Haan) ; Thalamonyx, A . Milne Edwards. 
Subfamily 2. Thalamitiisle. 
Thalamitiens, A. Milne Edwards (pt.), Archiv. Mus. Hist. Nat., voL x. p. 311, 1861. 
Carapace widely transverse, antero-lateral margins usually straight, forming a right 
angle with the front, with few (four or five) teeth. Basal antennal joint greatly 
developed, widely transverse, flagellum widely excluded from the orbit. Chelipedes 
moderately elongated. Fifth legs natatorial, as in the Lupinae. 
Genera : — Thalamita, Latreille ; Thalctmitoides, A. Milne Edwards ; ? Hedroph- 
thalmus, Nauck. 
Subfamily 3. Caucinina:. 
Garciniens , Polybiens, Lissoccirciniens, A. Milne Edwards, Arcliiv. Mus. Hist. Nat., vol. x. 
p. 311, 1861. 
Carapace but slightly (if at all) transverse, with the antero-lateral margins arcuated 
and armed with five or fewer marginal teeth. Basal antennal joint moderately 
developed. Chelipedes rather small. Fifth legs natatorial (except in Carcinus). 
1. Antennae not wholly excluded from the orbits. 
Genera : — Portunus, Fabricius (Liocarcinus, Stimpson, subgenus ?) ; Bathynectes, 
Stimpson ( = Thranites, Bovallius) ; Nectocarcinus, A. Milne Edwards ; 
Carcinus, Leach ; Platyonychus, Latreille ( = Anisopus, de Haan) ; Portum- 
nus, Leach ( = Xaiva, MacLeay) ; Polybius, Leach; Lissocarcinus, Adams 
and White. 
2. Antennae wholly excluded from the orbits by the union of the front with the 
inferior orbital margin. 
Genus :—Ceenophthalmus, A. Milne Edwards. 
Subfamily 4. Caphyriile. 
Carapace but slightly (if at all) transverse, with the antero-lateral margins arcuated, 
and armed with only four or five teeth. Basal antennal joint moderately developed. 
