478 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



higher and rounded. The second to fifth antero-lateral teeth or lobes are 

 similar to those of mercenaria except that the second is more advanced, 

 more transverse, and is subdivided by a shallow sinus into two lobules. 



On the upper distal quarter of the inner face of the palm there is an 

 oblong patch, vertically placed, of parallel oblique striae. There are 

 certain fixed points on the carapace against which the striae may be 

 scraped; they are small tubercles, mostly oblong and whitish, situated 

 as follows: One oblong on the lower surface of the median and outer 

 suborbital lobes, two further back near the angle of the buccal cavity; 

 and just below the antero-lateral margin one small tubercle on each 

 lobule of the second lobe and two or three on the third lobe or tooth. 

 This stridulating apparatus is present on a specimen only 18 mm. wide. 

 Black of fingers not covering their base but ending in an irregular, 

 mostly scalloped line. 



Color. — General color of preserved specimens red. Outer face of 

 manus reticulated with yellow. 



Measurements. — Male (60758) total length of carapace 86, width of 

 same 128, fronto-orbital width 45.6, width of front 20.8 mm. 



Range. — West coast of Nicaragua to Peru. 



Material examined. — Nicaragua; Dr. Carl Flint; 1 female (3812). 



Panama: J. H. Sternbergh collector; 2 males, 1 female (17300). 

 Chame Point; June-July, 1912; Robert Tweedlie, Smithsonian Bio- 

 logical Survey; 1 young (59310). Canal Zone; August, 1915; J. 

 Zetek; 1 male, paper shell (48807). 



Paita, Peru; under rocks, low tide; October 8, 1926; W. L. Schmitt; 

 3 males, 19 females (60758); a fine series of large specimens, the first 

 recorded from Peru. 



Locality unknown; 1 male (13885). 



MENIPPE OBTUSA Stimpson 



Plates 197; 198, Figures 1 and 2 



Menippe obtusa Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1859, p. 53 [7] 

 (type-locality, Panama; type, Cat. No. 2050, U.S.N.M.). 



Diagnosis. — A single lobule on frontal margin next to each sub- 

 median lobe. Front channeled just above the lobes. Second antero- 

 lateral lobe bilobate. Stridulating organ of palm unhke in the sexes. 



Description. — Carapace nearly smooth and even, flattened posteri- 

 orly; a tubercle on each side of front and of epigastric region. Gas- 

 tric region defined. Frontal region channeled along the margin 

 above the lobes. A single lobule behind each frontal lobe, forming 

 an oblique row with the obtuse, tuberculiform inner angle of orbit. 

 Outer angle of orbit low and blunt; the tooth below it blunt and a 

 little more advanced; tooth at inner lower angle large and rounded. 

 Between these last two, on ventral surface and not projecting to 

 orbital margin there is a tubercle. Antero-lateral teeth similar to 

 those oi frontalis, but the second lobe is bilobate. 



