1352 



CRUSTACEA. 



gero longiore quam sequens, dentibus tribus fere conicis. Pedes 8 pos- 

 tici crassi, ramis bad vix longioribus. 



Carapax oblong elliptical, covering all the feet. Abdomen oblong, 

 nearly half as wide as carapax, behind very deeply two-lobed, the 

 lobes reaching to middle of the abdomen and subacute behind. 

 Anterior branch of antennae with the second joint uncinate at apex, 

 and bearing a spine both on the anterior and posterior side; also, a 

 spine at base, another behind base, and still another more exte-* 

 riorly, from which the posterior branch of the antennas proceeds. 

 Feet of second pair very stout, third, fourth, and fifth joints hardly 

 oblong, the dentigerous basal joint longer than the next following, 

 and the three teeth behind subconical. Eight posterior feet stoutj 

 the branches hardly longer than the base. 



Plate 94, fig. 2 a, dorsal view of animal, enlarged ; b, ventral view. 



Puget's Sound. 



Length, two-thirds of an inch. The base of the second pair of feet 

 has a tooth on the inner side of base, in addition to the three which 

 form the posterior margin of the basal portion. 



Family II. CALIGID^. 



Subfamily CALIGLNJE. 



Genus CALIGUS, Muller. 



In characterizing species of Caligus, it is important to note that the 

 sexes differ widely : — 



1. In the form of the posterior antennae, these organs being simply 

 uncinate at apex in females, and two-clawed in males. 



2. In the form and size of the second pair of legs, the hand being 

 very stout and usually didactyle in males, and much less stout and 

 monodactyle in females. 



