58 NEW-YORK FAUNA CRUSTACKA. 



Genus Caligus, Mullcr. 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. AntenUcB 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. (Pickering & Dana, Am. Jour. So. Vol. 34, pi. 3, 4 and 5. Pl. 10, fig. 46 

 (male) and fig. 47 (female) of this work.) Oval-oblong. Length, "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. 437. Gould, 1. c. 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. crisiatus. (Gould, 1. c. p. 340.) Two little elevated crests within each posterior angleof the shield, 

 at right angles to each other. Abdominal and caudal plates very long and broad. Margin of shield 

 behind the antcnnce, thin, and minutely fringed. Total length, with the caudal appendages, 1'5. 

 Dr. Gould suggests that it may prove to be Plerygopoda latreilli. Attached to Lamna punctata. 



GENUS ANTHOSOMA. Leach. 



Shield suborbicular. Antennae 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 smithii. Leach, Diet. Sc. Naturelles, Vol. 14, p. 533. 



A. id Griffith's Cuvier's RJgne Animal, Vol. 13, p. 374, plj 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 cornuhica ; then by Risso {Ichthyol. p. 38), on the Squalus 

 firox ( Scyllium) ; and subsequently by Storer, on the Lamna -punctata of our coast. 



