DECAPOD CRUSTACEANS OF THE BEAUFORT, N. C, REGION. 435 



margins of which are minutely denticulate; front produced beyond internal orbital teeth and with three 

 teeth of which the middle one is longer than the others and depressed ; orbits circular, with two narrow 

 fissures above and two below, the suborbital lobe being strongly produced. 



Chelipeds about as long as second pair of legs, stout; carpus and hand with strong, granulose rugae; 

 carpus with a sharp spine at its inner angle; hand smooth on inner face, heavily rugose on outer face; 

 two rugse continued from hand onto the finger which is slaty black at the tip and somewhat deflexed. 

 Ambulatory legs short, fringed beneath, the dactyli tipped with black. 



Length, 62 mm.; width, gi mm. 



Color, yellowish beneath, brick-red above; back with two curved lines of yellowish spots, and 

 behind the middle, a figure somewhat resembling the letter H. The legs are mottled and reticulated 

 with yellow and brick-red and more or less purplish. 



Small and immature specimens of this species are sometimes dredged in depths from 3 to 5 fathoms 

 within the harbor. Larger specimens have been obtained in deep water off the coast. 



Cancer irroratus Say. Northern rock crab. PI. xxxv, fig. i. 



Cancer irroratus Say, 1S17 [pt.], p. 59; Stimpson, 1859, p. 50: Coues, 1871, p. 120; Kingsley, 1878-79, p. 317; Paulmier, 1905, 

 p. 139: Sumner. 1911, p. 671: Fowler, 1912, p. 429. pi. 134, 135. 

 Platycarcinus irroratus H. Milne-Edwards, 1834-1840, t. I, p. 414. 

 Cancer sayi Gould, 1S41. p. 323. 

 Platycarcinus sayi De Kay, 1S44, p. 7. 



Carapace about two-thirds as long as wide, convex, granulated; anterolateral border divided into 

 nine teeth whose margins are granulate, not denticulate as in C. borealis, and the notches between the 

 teeth are continued onto the carapace as short-closed fissures, giving a pentagonal character to the teeth; 

 posterolateral border a granulated ridge having at its outer end one tooth similar to those of the antero- 

 lateral border but smaller; front with three teeth, of which the middle one exceeds tlie others and is 

 depressed. Abdomen of male broad ; first, second, and third segments with a transverse granulated ridge. 



Chelipeds of moderate size, not as long as the second pair of legs; carpus with granulated ridges and 

 with a sharp spine at the inner distal angle; hand nearly smooth on inner face, outer face with four or 

 five granulated lines, two of which are continued onto the finger, while the superior one is cristate. 

 Ambulatory legs rather long and slender, meros of first and second pairs extending far beyond carapace. 



Length, 65 mm.; width, 95 mm. 



Color, yellowish, closely dotted with dark purplish brown, which becomes reddish brown after death. 



This crab is rare at Beaufort and the few specimens which have been obtained are immature. At 

 ■ some distance from the coast larger individuals have been dredged up. Both this species and the 

 preceding one are members of a northern fauna, and except in deep water do not extend much farther 

 south than the Carolina coast. 



Family XANTHIDAE. 



Brachyrhyncha having the body usually transversely oval, the last pair of legs 

 normal, the first pair of antennae folding obliquely or transversely and the male openings 

 rarely sternal. 



This very large family of crabs comprises at the present time 106 genera. Of this 

 number 1 1 are represented in the Beaufort region. 



KEY TO THE GENERA OF THE BEAUFORT REGION.^ 



a. Frontal margin presenting but a single edge, not transversely grooved. 

 b. Carapace naked or lightly pubescent, front granulate or smooth, teeth of anterolateral borderusually 

 flattened and subtriangular. 



a While in most of the keys in this paper it has been possible to utilize generic characters and to show to some extent the 

 accepted ideas of the relationship of the genera, it has been impossible to do so in the case of the family Xanthidae. The diflerences 

 between the genera into which the old genus Panopeus has been divided are either too subtle to be appreciated, except after long 

 study of the species, or are to be found in a combination of characters no one of which can always be depended upon. It has 

 therefore been necessary to make use of the most trivial characters and, since each genus, with the exception of Pitumnus, is 

 represented in the Beaufort fauna by a single species, the key is really a key to the species. 



