162 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



'LEUCOSIIDAE?, genus and species indeterminable. 



Plate 60, figs. 7 and 8. 



Locality Panama Canal Zone. From near Mount Hope in ditch 

 through swampy ground. About one-quarter mile from present sea 

 beach, 6 to 8 feet above high tide. Pleistocene series. D. F. Mac- 

 Donald, collector. April, 1911. Station 5850. Cat. No. 324236, 

 U.S.N.M. 



Matei^ial. Dactylus of left chela, 11.4 mm. long, with proximal 

 end lacking. This dactylus differs from those of Persephona and 

 allied genera in its strong curvature upwards, supposing the pre- 

 hensile edge to be directed inwards. This edge is nearly straight 

 except just at the tip and is armed with 25 small unequal teeth, 2 of 

 which in the proximal third are the largest. Besides this edge the 

 surface is composed of 4 high, smoothly rounded ridges separated 

 by narrow grooves; 2 of the ridges are inferior, and 2 superior, the 

 outermost of the latter embracing the outer edge and having a longi- 

 tudinal row of punctae near its middle. Each side of the prehensile 

 edge there are 2 or 3 rows of punctae. Tip of finger bent rather 

 abruptly but obliquely inward, while in its upward trend it continues 

 the curve of the rest of the dactylus. 



Subtribe BRACHYGNATHA. 



Superfamily BRACHYRHYNCHA. 



Family PORTUNIDAE. 



CALLINECTES DECLIVIS, new species. 



Plate 66, figs. 1-3. 



Type-locality. Banana Eiver, Costa Rica. Eighth fossiliferous 

 zone below the uppermost one of the section. Probably equivalent 

 to Gatum formation. Miocene series. D. F. MacDonald, collector. 

 1911. Station 5882i; 5c. Cat. No. 324262, U.S.N.M. 



Measurements. Greatest height, 14 mm.; length of manus meas- 

 ured horizontally from extreme base of proximal spine, 21 mm.; 

 thickness, 9.2 mm. 



Holotype. The propodus of the left cheliped, with the tip of the 

 finger broken off. The palm is prismatic as in recent species of 

 Callinectes, with 7 facets, more or less distinct ; 4 facets on the outer 

 surface and 3 on the inner surface. The surface, or what remains of 

 it, is smooth and shining to the naked eye, but under a lens, shows 

 very fine granulation, and larger scattered punctae. The facets are 

 separated by blunt ridges; one facet is a little above the middle of 



