254 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



long. The pleon and urus together are equal in length to half of the 

 pereion without the head. 



"The uropoda do not reach to the hinder margin of the urus. The 

 peduncle is shorter than the inner ramus. The inner ramus is longer 

 than the outer. 



"Color. Yellowish-white, with smaller and larger brown-red spots 

 on the anterior part of each segment; the posterior part is almost 

 white. 



"Length. The female virgo, 17 mm. 



"The males, 12, 15, 16 mm." BOVALLIUS." 



CYMOTHOA OESTRUM (Linnaeus). 



Oniscus oestrum LINN.EUS, Syst. Nat., 10th ed., I, 1758, p. 636, No. 2; Fauna sue- 

 cica., 2d ed., 1761, p. 499, No. 2053; Syst. Nat., 12th ed., I, 1767, Pt. 2, p. 

 1059, No. 2. 



Asellus oestrum OLIVIER, Encycl. Method., IV, 1789, p. 253. 



Cymothoa oestrum FABRICIUS, Entom. Syst., II, 1798, p. 505, No. 6. LEACH, Trans. 

 Linn. Soc. London, XI, 1815, p. 372; Diet. Sci. Nat., XII, 1818, p. 352. 



Cymothoa dufresnei LEACH, Diet. Sci. Nat., XII, 1818, p. 352. 



Cymothoa immersa SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 399-400. 



Cymothoa oestrum DESMAREST, Consid. Gen. Crust., 1825, p. 309, pi. XLVII, figs. 

 6-7. MIERS, Proc. Zool. Soc., 1877, pp. 671-672. SCHKEDTE and MEINERT, 

 Naturh. Tidsskr. (3), XIV, 1883-84, pp. 271-279, pi. vm, figs. 5-13. 

 RICHARDSON, American Naturalist, XXXIV, 1900, p. 221; Proc. U. S. 

 Nat. Mus., XXIII, 1901, p. 530. 



Localities. Caribbean Sea and Gulf of Mexico to shores of Virginia; 

 Swan Island; St. Bartholomew; St. Christopher; Jamaica; Guade- 

 loupe; St. Georges, Bermudas; St. Anna, Mexico; Key West, Florida; 

 Curacao, Venezuela; Peru; Barbados (from stomach of a "redfish"). 



Parasite of Caranx latus, "jackfish" (from branchial cavity); red- 

 fish (stomach); in the tongue of Scombroid fishes; from the mouth of 

 Priacanthus arenatus and Trachurops crwnenophthalmus; on Strombus 

 giganteus. 



Body oblong-ovate, twice as long as wide, 15 mm. : 30 mm. 



Head, wider than long, 4 mm. : 6 mm., with the antero-lateral angles 

 rounded and the anterior margin appearing straight from a dorsal 

 view, but actually being somewhat triangularly produced and bent 

 downward over the antennae. The head is deeply set in the first tho- 

 racic segment, the broad and widely rounded antero-lateral angles of 

 which extend to the anterior margin of the head. The eyes are absent, 

 and no traces of them are seen. The first pair of antennas are com- 

 posed of eight articles and extend a iittle beyond the middle of the 

 head. The second pair of antennae are composed of nine articles and 

 extend two articles beyond the first pair of antennae. The basal arti- 



aBihang till K. Sv. Vet.-Akad. Handl., X, No. 11, 1885, pp. 28-29. 



