THE SPIDER CRABS OP AMERICA 



459 



Old. — The old have a longer and thicker pile, especially on the 

 chelipeds, which attain a length more than twice as great as the 

 carapace, and are very stout, palm compressed. 



Half grown. — Comparing a half-grown male (16053) with Saiis- 

 sure's figure of a little larger specimen of spinosissima, spinimana is 

 seen to have the greater number of spines, while both have fewer 

 spines than the full grown of the same species. Median spines of 

 spinimana 11,1 more (gastric) than in spinosissima. Large anterior 

 hepatic spines only 2 (as in spinosissima) but with a small spine or 

 spinule where the innermost large spine occurs in the old. 



Younr/. — Besides the eight specimens above described, all those in 

 the National Museum are very small and immature and present a 

 very different appearance, as at least half of the spines which are 

 evident later are undeveloped. The hepatic region is not enlarged 

 nor produced (in this respect resembling typical Stenocionops) and 

 bears only one large marginal spine and a very small one in front 

 of it. There are only 2 large spines on the branchial margin, as in 

 S. contigua; one small spine on the posterolateral margin; 2 or 3 

 spines high up on the branchial region. Surface of basal antennal 

 article mostly concave. 



Measurements. — 



Largest 

 d, Sta. 

 20037 



Large d" , 

 holo- 



type of 

 spini- 

 mana 



Half 



grown c? 



(16053) 



Young 9, 



holo- 



type of 



atlantica 



Length of carapace, including horns 

 Width of carapace, including spines 

 Width of carapace, excluding spines 

 Length of rostral horns 



130 



118.2 



110.4 



10.5 



10.2 



53 

 42 

 35.6 

 9.5 



17.6 

 12.6 

 10.4 

 3.2 



Range. — From off Cape Hatteras, North Carolina, to Florida 

 Straits and Gulf of Mexico. Depth, 20 to 124 fathoms. 

 Material examined. — See table, page 458. 



STENOCIONOPS OVATA (Bell 



Plate 264, figs. 5-7 



Pericera ovata Bell, Proc. Zool. Soc. London, vol. 3, 1835 (1836), p. 173; 

 Trans. Zool. Soc. London, vol. 2, 1836, p. 60, pi. 12, figs. 5, 5o, 5p, 5^ 

 (type-locality, Galapagos Islands, 6 fathoms; type not extant). 



Stenocionops ovata Rathbun, Proc. U. S. Nat. Mus., vol. 38, 1910, p. 574. 



Diagnosis. — Median spines of carapace 8. Lateral marginal spines 

 4 or 5. Size small. Horns divergent. 



Description. — Female: Carapace elongate-oval, sparingly covered 

 with short close hair; four small spines on median line of gastric 

 region, three spines on cardiac and genital regions, the middle one 

 being the largest, one spine on the intestinal, a very small one on 



