CALIFORNIA STALK-EYED CRUSTACEA. 71 



Portunus Xantusii (St.) 



Achelous Xantusii STIMPSOX, Ann. N. Y. Lye. Nat. Hist., Vol. VII, 1860, 



p. 222. 

 Neptunus asper A. MILNE-EDWARDS, Arckiv. du Mus. Hist. Nat. Paris, 



T. X, I860, p. 325, PI. XXX, fig. 3. 

 Neptunus Xantusii A. MILNE-EDWARDS, 1. c., 1860, p. 429; Crust, in Miss. 



Sci. au Mex., Pt. V, p. 213, PI. XXXVIII, fig. 1, and PI. XXXIX, 



fig. 3. 

 Amphitrite paucispinis LOCKINGTOX, Proc. Gal. Acad. Sci., Vol. VII, 1877, 



p. 107. 

 Portunus Xantusii EATHBUN M., Proc. U. S. Nat. Mns., Vol. XXI, 1898, 



p. 593. 



Carapace markedly transverse, the upper surface pubescent. Gastric 

 area with a median granulated line and a transverse line, near the middle, 

 which is slightly concave in front; the posterior portion crossed by a 

 short transverse line; a granulated line beginning near the posterior part 

 of the gastric area, at first arching forwards, and then curving backwards 

 near the side of the carapace and extending upon the large lateral spine; 

 two short, oblique, parallel lines on the branchial areas; on the cardiac 

 region there are two short transverse lines situated end to end, their inner 

 extremities curving backwards and meeting to form a longitudinal, median 

 line which is often obscure. Front short and not projecting beyond a 

 line drawn across the tips of the acute triangular projections of the infe- 

 rior margin of the orbit, the four frontal teeth are equally prominent, the 

 two middle ones slightly narrower than the outer pair and separated from 

 the latter by a slightly wider interval than they are separated from each 

 other. The tooth at the inner angle of the orbit is double pointed. The 

 postorbital tooth is larger than the one behind it and extends nearly as 

 far forward as the teeth of the front. The antero-lateral teeth are sharp 

 and curved forward and show a tendency to alternate in size; the lateral 

 spine is about three times as long as the tooth in front. Upper margin of 

 the orbit with two fissures and a small tooth on the inner side of the outer 

 fissure. A single fissure in the lower orbital margin external to which is 

 a small cusp upon the under side of the postorbital tooth. Chelipeds 

 pubescent, merus armed in front with four to seven spines; posterior mar- 

 gin scabrous but not spiny, with the exception of a small spine at the dis- 

 tal end; carpus with several granulated ridges on the outer surface; a 

 strong spine at the distal end of the upper margin and a smaller spine on 

 the lower side at the distal end of the lowest granulated ridge; hand fur- 

 nished with a spine at the external hinge joint; the granulated ridge on 

 the upper margin terminates in a spine a little behind the distal end of 

 the palm; four granulated ridges on the outer surface of the hand not 

 counting the upper one; fingers strongly ridged, teeth dark colored; first 



