54 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Carapace either longer than broad and convex, or broader than long 

 and fiattish, the lateral borders well defined. Front broadly trian- 

 gular, sometimes notched at tip. Antennal flagella not so long as 

 carapace. External maxillipeds typically opercular, completely clos- 

 ing the buccal cavern. Chelipeds equal or slightly unequal, generally 

 stouter than legs. First three pairs of legs stout, about as long as 

 chelipeds; fourth pair dorsal and rudimentary. The abdomen in both 

 sexes consists of seven segments, and there is a pair of lateral platelets 

 intercalated between the last two segments. The gills are phyllo- 

 branchiate. The sternal grooves of female end at level of genital 

 openings. (After Alcock.) 



KEY TO THE GENERA OF THE FAMILY DYNOMENIDAE 



A^ Carapace flattish, broader than long, pilose Dynomene (p. 54) 



A'. Carapace convex, longer than broad, spinose Acanthodroinia (p. 55) 



Genus DYNOMENE Latreille 



Dynoyneve Latreille, in Desmarest, Considerations g^ndrales sur la classe des 

 Crustac^s, p. 133, footnote, 1825; in Cuvier, Le regne animal, ed. 2, vol. 4, 

 p. 69, 1829 (type, D. hispida Desmarest). — Milne Edwards, Histoire natu- 

 relle des Crustaccs, vol. 2, p. 179, 1S37. — Ortmann, in Bronn's Klassen und 

 Ordnungcn des Thier-Reichs, vol. 5, pt. 2, Arthropoda, p. 1155, 1901. — 

 Alcock, Journ. Asiat. Soc. Bengal, vol. 68, pt. 2, p. 133 and synonymy, 

 1S99; Catalogue of the Indian decapod Crustacea in the collection of the 

 Indian Museum, fasc. 1, p. 35, 1901. 



Maxillothrix Stebbing, Ann. South Afr. Mus., vol. 18, pt. 4, p. 456, 1921 (type, 

 M. adaeijormis Stebbing). 



All parts usually tomentose. Carapace subcircular or polygonal, 

 flattish, slightly broader than long. Front broadly triangular, dor- 

 sally grooved, more or less distinctly notched or divided at tip. 

 Palate weU delimited from epistome ; efferent branchial channels well 

 defined. Feet of fourth pair very small, not prehensile, dorsal in 

 position and inconspicuous. 



Indo-Pacific, from Mauritius and Madagascar to Mexico; tropical 

 Atlantic in neighborhood of Cape Verde Islands. 



DYNOMENE URSULA Stimpson 



Plate 12, Figures 1-4 



Dynomene Ursula Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, p. 239 [111] 

 1860 (type locality. Cape St. Lucas; type not extant). 



Diagnosis. — Lateral margin of front regularly curved, not sinuate. 

 Dactyls of first three ambulatories setose, tips black. Hind pair of 

 feet setose like the others, dactyls without pigment. 



Description. — The whole upper surface is covered with stout thick 

 setae of two kinds; the first kind very short, clavate, or even pedicel- 

 late, and densely crowded; the second long and nearly as thick as the 

 first, but fusiform, with pointed extremities, and sparsely distributed 



