124 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



ends dentiform. In the orbital wall there are, as usual, three sutures, 

 and a gap at inner can thus; edge of roof of orbit more or less emar- 

 ginate. The antennules fold obliquely or nearly transversely. Anten- 

 nae minute but distinct. Buccal cavern moderately elongate; the 

 exopodite of external maxillipeds not dilated, its outer edge a little 

 curved; triangular merus of external maxillipeds about three-fourths 

 length of ischium measured along inner border. Chelipeds variable, 

 usually massive; in the typical forms short, not much more than half 

 again as long as carapace, and stout, with short, broad hands not 

 differing much in length from the stout, compressed fingers. (After 

 Alcock.) The abdomen of the male consists of three pieces, of the 

 female of four pieces in the American forms, and the male has a sharp 

 spine at proximal end of sixth segment. 

 Atlantic, Indian, and Pacific Oceans. 



KEY TO THE AMERICAN SPECIES OF THE GENUS EBALIA 



A^ Carapace hexagonal or subglobular stimpsonii (p. 124) 



A2. Carapace octagonal. 



B'. Carapace not posteriorly excavate. 



C^ A narrow, granulated ridge extends upward from the lateral 

 tootli toward the highest part of the branchial region. 

 D^ Last three articles of cheliped not cristate. Posterior 



lobes of carapace subglobular cariosa (p. 125) 



D^. Merus of cheliped cristate. Posterior lobes of carapace 



subtriangular magdalenensis (p. 128) 



C^. No narrow, granulated ridge extends upward from the 

 lateral tooth. 

 D'. A broad, sharp crest on last three articles of chelipeds. cristata (p. ] 32) 

 D^. A low inconspicuous crest on last three articles of 

 chelipeds. 

 El. Two triangular teeth on lateral margin of carapace at 



its widest part hancocki (p. 128) 



E'. No marginal teeth on carapace at its widest part, clarionensis 



(p. 132) 

 B^. Carapace deeply excavate about cardiac region rotundata (p. 135) 



analogous species of ebalia on opposite sides of the continent 



Atlantic Pacific 



cariosa. magdalenensis. 



EBALIA STIMPSONII A. Milne Edwards 



Figure 33; Plate 35, Figures 1-3; Plate 37, Figures 1-3 



Ebalia stimpsonii A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 22, 

 1880 (type locality, Barbados, 7>^-50 fathoms; type, M.C.Z. no. 2761).— 

 Rathbun, Bull. Lab. Nat. Hist. State Univ. Iowa, vol. 4, p. 293, 1898; 

 Bull. U. S. Fish Comm. for 1900, vol. 20, pt. 2, p. 87, 1901. 



Ebalia stimpsoni A. Milne Edwards and Bouvier, Mem. Mus. Comp. Zool., 

 vol. 27, p. 118, pi. 23, figs. 6, 7; pi. 24, fig. 2, 1902. 



Diagnosis. — Carapace more even than customary, depressed in 

 hepatic area only. An hepatic and a pterygostomian prominence. 

 Four posterior protuberances. 



