Figure 201. — Palicus faxoni (Rathbun). Male in dorsal 

 view, legs of left side not shown ; cheliped, second and 

 third walking legs detached ; first and fourth walking 

 lags from female in Rathbun (1918b) ; 5 mm. indicated. 



tooth somewhat obscured by ventrally bent ptery- 

 gostomian lobe, sharp pointed at tip; outer lobe 

 slightly convex. Posterior margin preceded by a 

 tuberculate ridge. 



Chelipeds in both sexes somewhat unequal, right 

 hand approximately twice as wide as left. Walk- 

 ing legs short and broad ; first three meral articles 

 with a large, flat, acute distal spine, posterior dis- 

 tal tooth of merits sharp; carpal lobes prominent, 

 distal one of second and third legs acute; pro- 

 podus of second and third legs widening distally, 

 dactyls wide, posterior margin sinuous. 



Measurements. — Carapace: male, length, 10 

 mm., width, 10 mm.; female, length, 10 mm., 

 width, 11 mm. 



Habitat. — Thirty-two to 51 fathoms. 



Type locality. — Off Cape Hatteras, N.C., 49 

 fathoms. 



Known range. — Type locality ; off Jacksonville, 

 Fla. ; off Yucatan, Mexico; off Cabo Frio, Rio de 

 Janeiro, Brazil ( ?). 



Family Grapsidae 



Front quite wide; carapace usually quadrilat- 

 eral, with lateral borders either straight or 

 slightly arched, and orbits at or near anterolateral 

 angles. Buccal cavern square; generally a gap, 



often large and rhomboidal, between external 

 maxillipeds. Male openings sternal. Palp of ex- 

 ternal maxillipeds articulating either at antero- 

 external angle or at middle of anterior border of 

 merus, exognath either slender or broad. Inter- 

 antennular septum broad. Division of orbit into 

 two fossae accented (Eathbun, 1918b). 



KEY TO SUBFAMILIES, GENERA, AND 

 SOME SPECIES IN THE CAROLINAS 



a. Antennules folding beneath front of carapace in usual 

 way. 



b. Third maxillipeds without a pubescent oblique ridge. 

 c. Lower border of orbit running downward toward 

 buccal cavern ( Subfamily Grapsinae). 

 d. Carapace decidedly broader than long. 



Pachygrapsus transversus (p. 217). 

 dd. Carapace about as long as broad ; legs strongly 



fringed with hairs Planes minutus (p. 218). 



cc. Lower border of orbit not running downward 

 toward buccal cavern, but supplemented by remote 

 suborbital crest in line with anterior border of 

 epistome (Subfamily Varuninae) 



Euchirograpsus americanus (p. 220). 



bb. Third maxillipeds with an oblique pubescent ridge 



crossing ischium and merus (Subfamily Sesarminae) 



Sesarma (p. 221). 

 aa. Antennules visible dorsally in deep clefts in front of 

 carapace (Subfamily Plagusiinae). 

 b. Carapace broader than long 



Plagusia depressa (p. 223). 

 bb. Carapace longer than broad 



Pcrcnon gibbesi (p. 224). 



Subfamily Grapsinae 



Front usually strongly deflexed. Lower border 

 of orbit running downward toward buccal cavern. 

 Antennal flagellum very short. External maxilli- 

 peds usually separated by a wide rhomboidal gap, 

 not traversed by an oblique hairy crest; palp 

 articulating at or near anteroexternal angle of 

 merus ; exognath narrow and exposed throughout. 

 Male abdomen filling all space between last pair 

 of legs (Eathbun, 1918b). 



Genus Pachygrapsus Eandall, 1840 



Rathbun, 1918b, p. 240. 



Pachygrapsus transversus (Gibbes). Mottled shore crab 



Figure 202. 



Orapsus transversus Gibbes, 1850, p. 181. 



Pachygrapsus transversus: Rathbun, 1918b, p. 244, pi. 61, 

 figs. 2-3 (rev.).— Hay and Shore, 1918, p. 447. pi. 36, fig. 9. 



Recognition characters. — Small species. Cara- 

 pace rectangular, about one-fourth broader than 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



217 



