92 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



PORTUNUS (ACHELOUS) SPINICARPUS (Stimpson) 



Plate 45 



Achelous spinicarpus Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, p. 148 (six 



type-localities in Florida, namely, off Tortugas, off Carysfort Reef, off Conch 



Reef, off Alligator Reef, off Pacific Reef, off American Shoal, and one in 



Georgia, lat. 31° 31' N., long. 79° 41' W.; depths ranging from 13 to 150 



fathoms; types not extant). 



Neptunus (Hellenus) spinicarpus A. Milxe Edwards, Crust. Reg. Mex., 1879, 



p. 221, pi. 40, fig. 1-16; Bull. Mus. Comp. Zool., vol. 8, 1880, p. 11 (Saba 



Bank excepted) . 



Porlunus (Achelous) spinicarpus Rathbun, Bull. U. S. Fish Comm. for 1900, vol. 



2, 1901, p. 47. 



Diagnosis. — -Inner spine of carpus of male longer than palm. No 



toothe at posterior angles of carapace. Marginal teeth narrow, spini- 



form. A spinuloiislobe atpostero-distal end of merus of swimming foot. 



Description. — Surface pubescent, granules on elevations beadlike, 



not crowded. Teeth of front and antero-lateral margin narrow, 



spiniform, separated by broad U-shaped sinuses. Of the frontal 



teeth those of the median pair are more advanced than those of the 



outer pair, which in turn overreach those at the inner angle of the 



orbit. This angle is bidentate but the outer denticle is low and blunt. 



Supra-orbital fissures V-shaped, a spine on the inner side of the outer 



fissure. The orbit has a strong dorsal aspect, the lower outer emargi- 



nation is a wide V. Lateral spine long, in the full grown as long as 



the width of the next four teeth. The second, fourth, and sixth teeth 



are somewhat reduced. 



CheUpeds of male 3 times as long as carapace; merus with 4 or 5 

 slender spines on inner margin and one spine at extremity of outer 

 margin. Carpus with a very small spine outside but a long flattened 

 swordlike spine at inner angle; it is curved and is bordered on its 

 lower concave margin with a fringe of hair ; it is longer than the manus 

 and in flexion fits between merus and manus. The superior spine of 

 the manus is small and is about at the distal fifth of the article; the 

 manus is dilated below the union of palm and finger. The postero- 

 distal angle of the merus of the swimming legs is irregularly spinulous 

 or denticulate, some of the denticles in the old male are situated on a 

 shallow lobe pointing distad. 



Sex and age variations. — The berried females examined run smaller 

 than the males, their chelipeds are shorter, only about 2^ times as 

 long as the carapace, the carpal spine does not reach beyond the 

 superior spine of the manus. 



In mature individuals the lateral spine is slightly curved forward; 

 in the young and half grown it is straight or nearly so, transverse or 

 du'ected slightlj^ backward. It is longer than in the old, as long as 

 five lateral teeth in the half grown, and as six teeth in the very young. 

 Color. — Half grown male (61265), sand gray and clay colored mottled 

 carapace; general cast of carapace cream buft' and pinkish buft", 



