104 STALK- AND SESSILE-EYED. CRUSTACEA 
Cymothoidea, Dana, U.S. Explor. Exped. xiv, Crust. part 11, p. 745, 
(1853). 
Body usually convex, oblong, or oblong-oval in form. Terminal 
segment of the abdomen large, often scutiform. Posterior pair of 
appendages large, lamellate, natatorial, and applied to the sides of the 
terminal segment. 
Family I. CYMOTHOIDA. 
Cymothoadiens parasites, M. Edw. Hist. Nat. Crust. i, p. 247, 
(1840). 
Cymothoide, Dana, U.S. Explor. Exped. xiv, Crust. part ii, p. 745, 
(1853). 
Body more or less oval and convex, with the abdomen 4-6 jointed, 
the segments, (the last excepted), very short. Head small. Antenne 
inserted beneath the head. Epimere conspicuous. All the legs ter- 
minating in a large curved claw. Caudal appendages free, placed 
laterally, very rarely ciliated. Branchie scarcely ever ciliated. 
Maxillipeds large, 8-4 jointed, operculiform, the terminal joints very 
small. 
Species parasitic. 
Sub-Family I, Cymornorn2. 
Cymothoine, Dana, U.S. Explor. Exped. xiv, Crust. part i, p. 746, 
(1853). 
Caudal appendages not ciliated. Segments of the abdomen free, 
CERATOTHOA. 
Cymothoa, Fabr. (part) Ent. Syst. u, p. 503, (1798); Leach, (part) 
Dict. Sci. Nat. xii, p. 352, (1818); M. Edw. (part) Hist. Nat. Crust. 
ili, p. 264, (1840). 
Ceratothoa, Dana, U.S, Explor. Exped. xiv, Crust. part i, p. 747, 
(1853). 
Body very convex. Head deeply encased in the anterior segment 
of the thorax, (the antero-lateral lobes of which do not, however, 
reach to its anterior margin), narrowed anteriorly, and subacute at the 
extremity, which does not cover the bases of the antenne. Abdomen 
at base very much narrower than the thorax, six-jointed, the first five 
segments very short, the last broad, transverse. First, (inner), pair 
