24 mr. e. j, miers on crustacea from [jan. 14, 



Oregonia hirta ? 



? Oregonia hirta, Dana, Amer. Journ. Sci. and Arts (ser. 2), xi. 

 p. 270 (1H51); U.S. Expl. Exp. xiii., Crust, i. p. 107, pi. iii. 

 fig. 3 (1852). 



Two specimens of an Oregonia were collected, both females, the 

 larger and mature example densely overgrown with sea-weed. 

 These agree in almost every respect with specimens of Oregonia 

 hirta, from California (Puget's Sound), in the collection ; but the 

 legs are rather more robust, and the branchial regions more convex. 

 The examination of males might show that they belong to a distinct 

 species ; for the present, however, they cannot be regarded as distinct. 



Japan, Cape Blunt, lat. 41°4l' N., long. 141° 0' E. (depth 35 

 fathoms). 



Pleistacantha, gen. nov.' 



Carapace triangular, convex, and spinose. Rostrum long and 

 slender, composed, as in Oregonia, of two spines, which are in con- 

 tact with one another to near their extremities. Eyes laterally 

 projecting. Orbits not defined, the inferior walls wanting, the 

 superior and posterior represented by two or three spines. An- 

 tennules long ; interantenuulary septum with a prominent spine pro- 

 jecting downward. Antennae with the basal joint extremely slender 

 and armed with three spines ; the flagellum long, reaching almost 

 to the extremity of, and visible in a dorsal view at, the side of the 

 rostrum. Ischium (or second) joint of the outer maxillipeds longer 

 than the merus-joint, which has a short spine at its antero-external 

 angle ; the exognath very slender. Legs, as in Egeria, very long ; 

 the anterior pair robust, with the fingers acute and meeting near 

 their apices along their inner margins, but leaving an hiatus at base 

 when closed. The ambulatory legs are slender, and diminish succes- 

 sively in length to the last pair; their terminal joints are long, slender, 

 and densely iiairy. The male postabdomen is 6-jointed, the inflexed 

 portion oblong, the terminal joint transverse and rounded at its 

 distal extremity. 



This genus must be placed near Oregonia, with which it is nearly 

 allied in the structure of the rostrum and orbital and antennal region ; 

 but it diifers in the convex and spinose carapace and greatly elon- 

 gated legs, which gives it more the aspect of Egeria, and would ne- 

 cessitate its being placed among the Macro])odiens in Milne-Edwards's 

 arrangement. From Egeria it diifers in the structure of the orbital 

 and antennal region, &c. 



Pleistacantha sancti-johannis, sp. n. (Plate I. fig. I.) 

 Carapace covered with very numerous small spines of uniform size ; 

 interspersed with these are longer spines, of which three are placed 

 in a transverse series on the front and one at the back of the gastric 

 region, two on the cardiac, two on the intestinal and about three on 

 each branchial region; there are also several longer spines placed be- 

 hind the eyes and on the sides of the branchial regions. Rostrum 

 ^ TrXeicrros, superl. of ttoXvs, many; and uKavQa, a spine. 



