Figure 156. — Cancer borealis Stimpson. Male in dorsal 

 view, reduced (after Smith, 1879). 



Color. — Yellowish beneath, red above; back 

 with two curved lines of yellowish spots and, 

 behind middle, a figure somewhat resembling 

 letter H; legs mottled and reticulated with yellow 

 and red, more or less purplish. 



Habitat. — Small and immature individuals are 

 found in the Beaufort, N.C., harbor region ; larger 

 individuals occur in deep water off the coast; be- 

 tween tides among rocks to 435 fathoms. 



Type localities. — Nova Scotia to Cape Cod. 



Known range. — Nova Scotia to south of Tor- 

 tugas, Fla. ; Bermuda. 



Remarks. — This species has a fossil record dat- 

 ing from the Miocene of North America (Mac- 



Kay, 1943). Ovigerous females are recorded in 

 June from southern Florida. 



Family Xanthidae 



Crabs with body transversely oval or trans- 

 versely hexagonal. Front broad, never produced 

 in form of a rostrum. Last pair of legs normal. 

 Antennules folding obliquely or transversely. 

 Male openings rarely sternal (Rathbun, 1930a). 



In the key to the genera of Xanthidae in the 

 Carolinas it has been impossible to use char- 

 acters which show the general relationships unless 

 pleopods of the males are employed . Differences 

 between genera are often subtle and the general 

 worker is, therefore, compelled to use a combina- 

 tion of trivial characters for identification. Be- 

 cause most of the genera occurring in the Caro- 

 linas contain a single species, the generic key is 

 in large part also a key to species. Parts of the 

 key have been adapted from Rathbun (1930a) 

 and Ryan (1956). 



Arrangement of the genera differs in some 

 respects from that of Rathbun and is based on 

 similarities and differences in the first pair of 

 male pleopods. In such arrangement I follow 

 broadly the arrangements of Stephensen (1945) 

 and Monod (1956). As in Rathbun (1930a) and 

 Monod (1956), no attempt is made to divide the 

 family Xanthidae into subfamilies, though at' 

 least three well-marked groups appear in the 

 Carolinas, and perhaps the third of these groups 

 (fig. 183) could be split into additional groups. 



KEY TO GENERA IN THE CAROLINAS 



a. Entire body and legs with surface deeply and intricately eroded, resembling piece of stony coral .Glyploxanthus (p. 185). 

 aa. Entire body and legs with surface not deeply and intricately eroded. 



b. Antennae widely separated from orbits Eriphia (p. 182). 



bb. Antennae not separated from orbits. 



c. Chelipeds with a large notch clearly forming an open hole between carpus and hand when viewed fronts lly with 



chelipeds fully pressed against body Carpoporus (p. 186). 



cc. Chelipeds without a large notch clearly forming an open hole between carpus and hand when viewed frontally 

 with chelipeds fully pressed against body. 



d. Extreme edge of frontal margin with shallow transverse groove, each half appearing double (under magnification), 

 e. Carapace more or less nodose in front, upper edge of frontal groove formed by line of nodules .Leptodius (p. 192) . 



ee. Carapace not nodose in front but with transverse ridges on dorsum Rhithropanopeus (p. 187). 



dd. Extreme edge of frontal margin not transversely grooved, each half presenting but a single edge (under magni- 

 fication). 



e. Teeth of anterolateral border subtriangular or with edges flattened and rounded; carapace never nodose, 

 f. Carapace with regions on dorsum defined; carapace not smooth to unaided eye. 



g. Major cheliped with a more or less conspicuous tooth at base of dactyl, tooth larger than adjacent 

 teeth and often of contrasting color. 



176 FISH AND WILDLIFE SERVICE 



