38 NEW-YORK FAUNA — CRUSTACEA, 
Genus Ampuiruor, Leach. Gcneral characters of the preceding. No setaceous appendix to the third 
joint of the upper antenne. Tail without fasciculated spines, armed with bifid spines at the 
tip. Hands of the two anterior pair oval. Inhabiting fresh and salt water. 
A. serrata. (Sav, 1. c. p. 383.) Antenne equal, short, stout; eyes large, approximated, suboval ; 
eighth, ninth and tenth segments of the body serrated ; three spines on the lower edge of the palm. 
Length, 0°4. Egg harbor, New-Jersey. 
A. dentata. (Iv. Ib.) Posterior edge of the dilated thighs strongly serrated; eyes distant above; 
clypeus obtuse; hand truncate at tip, destitute of prominent teeth, but with a few rigid hairs. 
Length, 0°3. Fresh water marshes. South-Carolina. 
A. punctalta. (Ip. Ib.) Lower antenne nearly as long as the body; hands oval, not dentated nor 
larger than the carpus. Body and antenne sprinkled with black points. Length, 0°35. Egg 
harbor, New-Jersey. 
Genus Cerarus, Say. Antenne very large and robust, nearly equal; the upper of four joints, the 
lower or lateral ones of five, Anterior pair of feet small, monodactyle; the second pair with 
a broad palm and a two-jointed thumb. Head distinct, ending in a small rostrum. 
C. tubularis. (Ip. p. 49. C. abditus, Tempieron, Tr. Ent. Soc. Lond. Vol. 1, pl. 20, fig. 5: See 
Pu. 10, fig. 43 0° this work.) Head with a mucronate carina before; hand and first joint of the 
thumb with one or two obtuse teeth; eyes oval, black. Color. Body above blackish, with irregu- 
lar paler spots; antennz and feet white; joints tipped with blackish: two hind pair of feet and tail 
white. Inhabiting a membranous tube open at both ends. Length, 0°25. Sea-beach, Egg 
harbor, New-Jersey. 
Genus Leripactyris, Say. Upper antenne with a setaceous appendix at the tip of the third joint. 
Head produced into a point. Body compressed, oval. Feet fourteen. Two anterior pair of 
feet simple, equal; third and fourth subequal, didactyle, fingers lamelliform; the remaining 
pairs spinous, without nails. 
L. dytiscus. (Say, 1. c. p. 380.) Eyes orbicular; setaceous appendix reaching the tip of the fourth 
segment of the terminal joint; anterior pairs of feet hairy. Cvlor: Body, when recent, white, 
with a ferruginous short stripe within. Length, 0°15-—0+25. Coast of Georgia. 
Genus Unciora, Say. Upper antennz- robust, subpediform, with an articulated seta at the base of the 
fourth join’. Feet fourteen, of which the first pair are monodactyle, the second with adactyle 
compressed hands with two minute hooks at the tip; cox simple, not dilated. Allied to 
Podocerus. 
U. irrora‘a. (Ip. Ib. p. 289.) Eyes conspicuous, rounded. Hands of the anterior fect with a longi- 
tudinal palm and prominent tocth; those of the second pair compressed, ciliated, with a subtriangu- 
lar hand. Color, when recent, pale with numerous red points. Length, 0°3. Hab. seaweed on 
the coast of New-Jersey. 
