264 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Habitat. — Lives in oven-shaped cavities or dens formed in the upper 

 surface of Uving corals; the opening of the den is usually semicircular 

 or lunate, commonly oblique to surface of coral. The downturned, 

 rough, and dirt-covered front of the crab serves as an operculum, 

 closing the aperture. Full-grown crabs are probably unable to leave 

 their dens. 



Range. — Bermudas; Straits of Florida; Dominica, B. W. I., 3 to 5 

 fathoms. Ilha das Rolas, off St. Thomas Island, Gulf of Guinea. 

 (Balss.) 



Material examined. — Tortugas, Florida; gift of Carnegie Institution: 



Symbiotic on coral, Meandra areolata; July-August 1925; H. 

 Boschma; 5 males, 11 fem.ales (2 ovigerous) (59964). In mouth 

 ridges of Meandra; July 1925; H. Boschma; 1 male, 2 females (1 

 ovigerous) (59973). August 1927; Wm. H. Longiey; 1 female 

 (61517). Seven corals with burrows containing crabs; Bush Key 

 Reef; station 21; 1926; C. R. Shoemaker; 4 males, 8 females (4 

 ovigerous) (67747). From Meandrina; Bush Key Reef; station 29; 

 July 23, 1930; Mr. Visscher; 3 ovigerous females (67748). In stomach 

 of Fish no. 280, Apogon sellicauda Evermann and Marsh; off N. end of 

 Loggerhead Key; June 9, 1925; W. L. Schmitt; 1 male (67749). 

 From Meandrina; off E. side of Loggerhead Key; station 31 ; July 18, 

 1931; W. L. Schmitt; 2 females (67750). 



Subtribe Brachygnatha De Haan 



Brachygnatha De Haan, in Franz de Siebold, Fauna Japonica, pp. xi-xiii, 

 1850. — BoRRADAiLE, Proc. Zool. Soc. London, 1900, p. 571; in J. Stanley- 

 Gardiner, The fauna and geography of the Maldive and Laccadive Archi- 

 pelagoes, vol. 1, pt. 4, pp. 425, 426, 1903; Ann. Mag. Nat. Hist., ser. 7, vol. 

 19, pp. 466, 468, 477, 1907.— Rathbun, U. S. Nat. Mas. Bull. 97, p. 14, 1918. 



Last pair of legs normal, rarely reduced, not dorsal, except in 

 Cymopolia and Retropluma. Female openings sternal. First abdom- 

 inal limbs of female wanting. Gills few. 



Superfamily Brachyrhyncha Borradaile 



Brachyrhyncha Borradaile, in J. Stanley Gardiner, The fauna and geography 

 of the Maldive and Laccadive Archipelagoes, vol. 1, pt. 4, pp. 425, 426. 1903; 

 Ann. Mag. Nat. Hist., ser. 7, vol. 19, pp. 468, 479, 481, 1907.— Rathbun, 

 U. S. Nat. Mus. Bull. 97, p. 14, 1918. 



Fore part of body broad. Rostrum usually reduced or wanting. 

 Body oval, round, or square. Orbits nearly always well inclosed 



