58 NEW-YORK FAUNA — CRUSTACEA. 
Genus Catiaus, Muller. Body elongated, depressed, and apparently divided into two parts: the an- 
terior covered by a shield in a single piece; the posterior oval or oblong, often with terminal 
lamellar appendages, and in the female with two long filiform appendages, Feet ten to four- 
teen, of two kinds: the anterior pairs unguiculate; the posterior lamellar, natatory and pecti- 
nated. Antenne two, very small, setaceous. Eyes two, distant, and placed under the anterior 
rim of the shield. Mouth forming a sucker externally as in the preceding, bent downwards, 
pectoral. Parasitic. 
C. americanus. (Pickertnc & Dana, Am. Jour. Sc. Vol. 34, pl. 3, 4 and 5. Px. 10, fig. 46 
(male) and fig. 47 (female) of this work.) Oval-oblong. Length, 0+5-0+6. Found attached to 
the outer surface of the M. americana, or common Cod-fish of our coast. 
C. piscinus, LATREILLE. (Say, Ac. Sc. Vol. 1, p. 487. Govzp, lc. p. 340.) Disk small and 
rounded, with two flattened jointed appendages behind, sometimes an inch long. Occurs on the 
cod and other marine fishes. Length, 0:2. Northern Coast. 
C. cristatus. (Goutp, |. c. p. 340.) Two little elevated crests within each posterior angle of the shield, 
at right angles to each other. Abdominal and caudal plates very long and broad. Margin of shield 
behind the antenne, thin, and minutely fringed. Total length, with the caudal appendages, 1°5. 
Dr. Gould suggests that it may prove to be Pterygopoda latreilh. Attached to Lamna punctata. 
GENUS ANTHOSOMA. Leach. 
Shield suborbicular. Antennz two, six-jointed. Feet twelve. Abdomen much narrower than 
the shield, with two foliaceous plates on the back, and six others beneath ; first pair of feet 
unguiculated, the tip opposed to a small tooth on the preceding joint; second pair with a 
compressed nail ; third pair with its last joint very thick, dentate in front. Beak a siphon. 
Two long caudal filaments. Parasitic. 
ANTHOSOMA SMITHII. 
Anthosoma smithit. Leacu, Dict. Sc. Naturelles, Vol. 14, p. 533. 
A. id Griffith’s Cuvier’s Régne Animal, Vol. 13, p. 374, pl: 21, fig. 3. 
Description. Whitish tinged with reddish ; the filaments of the tail slender, cylindrical, 
much elongated : the three posterior pairs form a case enveloping the post-abdomen. 
Length, 1:0. 
This small crustacean appears to be a parasite peculiar to the Shark family. It was first 
noticed by Leach on the Lamna cornubica ; then by Risso (Ichthyol. p. 38), on the Squalus 
ferox (Scyllium) ; and subsequently by Storer, on the Lamna punctata of our coast. 
