DECAPOD CRUSTACEANS OP THE BEAUFORT, N. C, REGION. 427 



Anterolateral teeth strong, acute, directed forward. Inner suborbital angle projecting as far as the median 

 tooth. Lower surface of carapace in the anterolateral region with a curved stridulating ridge. Abdomen 

 of male narrow, its sides nearly parallel; sixth segment more than twice as long as seventh, which is 

 circular; abdomen of female not greatly broader than that of male, widest at fifth segment. 



Chelipeds rather large; anterior margin of meros with several small spines and a dense fringe of 

 hairs; carpus with two spines, the inner one very strong; hand triangular, external border costate, internal 

 border with an overhanging densely ciliated ridge, which ends distally in a sharp spine; external costa 

 and internal line of cilia continued onto the dactyl. 



Measurements of a male: Carapace, length, 31 mm., width, 38 mm., thickness of body, 12.5 mm.; 

 length of cheliped, 42 mm. 



-Color, yellowish gray, closely set with small annular spots of reddish pxuple; carapace and chelipeds 

 with a silvery or brassy iridescence. 



The lady crabs are not often observed in the Beaufort region and probably are not as abundant as they 

 are farther north. On Bird Shoal and Shark Shoal and on the ocean beaches their cast-off shells are often 

 to be found, but these are of small size, and would seem to indicate that mostly immature individuals 

 come within reach of the ordinary collector. By the use of the dredge or otter trawl outside the inlet 

 many adult specimens have been obtained , and they appear to be fairly common about the fishing banks. 

 In the spring of 191 5 a number of specimens were obtained in the pound net set in Newport River, 

 about I mile north of the laboratory. 



Ovalipes ocellatus floridanus sub. sp. nov. PI. xxxii, fig. 8. 



Ovalipes ocellatus, VAT., Smith, 1887, p. 632. 



Holotype, No. 47937, U. S. Nat. Mus., J from Pensacola, Fla. Paratypes, No. 1791s. U. S. Nat. Mus. 



Differs from Ovalipes ocellatrts ocellatus in the lack of the purple ocellated spots, the color being a 

 imiform grayish yellow; the carapace is less arched and is evenly granulate all over, the median band 

 of enlarged granules not being evident; the anterolateral spines, especially the outer orbitals, are more 

 acute; the orbits are wider, the distance between the outer and inner orbital spines exceeding the dis- 

 tance between the suborbital spines, whereas in O. ocellatus ocellatus the reverse is usually true. The 

 broadening of the orbits appears to have been brought about at the expense of the interorbital part of 

 the carapace, the distance between the two inner orbital spines being slightly less than in typical 

 ocellattis from the north. 



' In the region about Beaufort, especially at a distance of a few miles off Cape Lookout, this form of 

 the lady crab is probably much more common than the spotted form. In the harbor it is very rare. 

 Specimens from the neighborhood of Cape Hatteras are not typical in all cases as regards measurements; 

 often the color is the only distinctive character. Along the Florida coast, judging from the collection 

 in the National Museum, the unspotted form is the only one that occiu-s. 



Genus PORTUNUS Weber. The pelagic crabs. 



Potiunus Weber, 1795, p. 93; Fabricius, 1798, p. 325. 



KEY TO THE SPECIES OP THE BEAUFORT REGION." 



a. Carapace wide; if the middle of the posterior margin be taken as a center and a circle drawn with 

 the length of the carapace as its radius, the periphery will fall well within the tips of the antero- 

 lateral spines (Subgenus Portunus). 



b. Interocular teeth six, the inner orbital being entire sayi. 



bb. Interocular teeth eight, the inner orbital being bilobed gibbesii. 



a Portunus and Achelous. — It is needless, in the present case, to attempt to settle the status of any of the groups into which 

 the genus Portunus has been divided. WTiether the form of the carapace, the shape and function of the anterior walking legs, the 

 articles of the third maxillipeds, or some other structural detail will furnish entirely satisfactory characters for a division can be 

 determined only by the critical study of a much more extensive collection of species than we have at our command. For the pur- 

 poses of this paper it appears to be best to follow Dr. Mary J. Rathbun in regarding Portunus, sensu strictu, as consisting of those 

 species with a broad carapace and A chelous as consisting of those with a narrow carapace, placing both as subgenera under 

 Portunus. It is doubtless true that this difference will not show in the case of very young individuals of some of the species, 

 but with reasonably mature and with all adult specimens there should be no trouble in making the distinction. 



