70 THE BRACHYURA. 
Outer sinus of orbit V-shaped; tooth at inner angle thickened. 
Chelipeds strong, unequal, rough with sharp granules which are very 
large on the wrist and hand. 
Inner angle of wrist blunt, not produced ; below it a sharp tooth; a deep 
sulcus parallel to distal margin. On the upper surface of the hand are two 
deep sulci; on the lower surface the granules are smaller and more de- 
pressed ; inner surface with a coarsely granulated area, reaching from the 
middle to the upper margin. Fingers deeply sulcate, dactylus granulate on 
basal portion in large cheliped, and on basal half in small cheliped. Fingers 
not gaping in small cheliped, slightly gaping in large one ; large dactyl with 
a strong basal tooth. . 
Legs spinulous. The merus has a single row of spinules on anterior 
margin, the carpus and propodus each three rows, but on these joints the 
spinules are obscured by hairs; upper surface of merus almost smooth, of 
next two joints more or less rough with sharp granules. 
Dimensions : — & type, length 7 mm., width 10 mm. ; fronto-orbital width 
5.7 mm., frontal width 3 mm. 
Type locality : —This species inhabits Taboguilla Id., Panama. The type 
¢, was taken at low tide at a depth of one fathom, from coral, Oct. 31, 1904 
(Cat. No. 32,859, U.S. N. M.). A much smaller ¢ was taken between tide © 
marks, Oct. 31, 1899. 
The nearest species is M. truncatifrons Rathbun’ from deep water in the 
Caribbean region, which has a horizontal front, the carapace with fewer hori- 
zontal markings and rougher behind, the inner prominences of the wrist 
spiniform, the legs much more slender. 
Xanthodius sternberghii Stimpson. 
Xanthodius sternberghii Stimpson, Ann. Lye. Nat. Hist. N. Y., 1859, 7, 52. 
Taboguilla Id. ; between tide marks; Oct. 31, 1899; 5 3, 7 °. 
Perico Id., Panama; Oct. 26, 1904; : é. 
Cycloxanthops vittatus (Stimpson). 
Xantho vittata Stimpson, Ann. Lye. Nat. Hist. N. Y., 1860, 7, 206. = 
Cycloxanthus vittatus A. Milne Edwards, Miss, Sci. au Mexique, Zool., 1879, pt. * & 
259, pl. 46, fig. 5. 
Perico Id., Panama, Oct. 26,1904; 1 ¢. 
1 Bull. Lab. Nat. Hist. State Univ. Iowa, 1898, 4, 274. 
