CRUSTACEA. 

 106 



cylindrical, instead of compressed and broad, and consequently, the 

 tarsus does not shut against this joint. _ 



The beak is bifid and long, with the horns in contact, and not 

 arcuate in a vertical plane like Eurypodius; though sometimes with 

 a slight curve in a horizontal plane. The eyes and post-orbital spine 

 are rather long, and the former closes back, reaching to the spine, 

 though not concealed in this position scarcely more than m Eury- 

 podius. The distance between the orbits is about twice the breadth 

 of the beak at base. The carapax has a triangular form, rounded 

 behind; it has the medial region tumid and prominent; a trans- 

 verse low post-medial region; a small cardiac region, and a large 

 swelling lateral region. The surface is rough, with minute granules 

 or obsolete tubercles, and short hairs arising from them, but without 

 any prominent spines, as far as the species have been observed. 



The septum between the inner antenna) is prolonged into a spinous 

 process. The epistome is large, but transverse. The buccal area, 

 is nearly square, the breadth slightly exceeding the length. The 

 third joint is triangular. The abdomen has seven joints in the male. 



Oregonia gracilis. 



Carapax breviter sparsimque piibescens, rostro valde longiore quam latL 

 tudo inter-orbltaUs. Pedes breviter sparsimque pubcsccntes, tenues; 

 prvmi secundis pernio brcriorcs, brachio tuferculls minutis supra infra- 

 que ornato, marm fere lineari, digito intus />/•<>/,< basin unidentoio 

 alioque dentictdato. Abdomen maris sublineare, margim laierali 

 versus apicem excavato, apice trtutcato. 



Carapax short and thin pubescent, beak much longer than distance 

 between the orbits. Feet short and thin pubescent, slender; first 

 pair a little shorter than second, arm with minute tubercles above 

 and below, hand nearly linear, finger having a small tooth within, 

 near base, and the rest of the edge denticulate. Abdomen of nude 

 sublinear, margin either side towards apex excavate, apex truncate. 



Plate 3, fig. 2 a, animal (male), natural size; &f under view, en- 

 larged; c, abdomen, natural size. 



Puget's Sound, C. Pickering. Exp. Exp. 



