GEOLOGY AND PALEONTOLOGY OF THE CAN*AL ZONE. 163 



the outer surface, and has subparallel margins ; the facet below this 

 widens distally and its lower edge, not very prominent, is continued 

 upon the finger, where it is sharper ; the lower facet of the outer sur- 

 face is not sharph- marked; the facet above the middle narrows 

 slightly toward either end and has raised margins; at its proximal 

 end there is the stout base of a large spine such as exists in Callinectes 

 of the present day. The upper facet of the inner surface is narrow, 

 wider in the middle than at the ends, and is not depressed, its distal 

 outer corner only is visible when the manus is viewed externally; 

 at the distal end just outside the inner margin is an indication that 

 a spine has been broken off. The remainder of the inner surface is 

 divided into 2 facets of nearly equal width separated by a prominent 

 ridge. 



The finger is a little curved inward; on the outer and inner sur- 

 face there are 2 grooves, each with a row of large punctae, the groove 

 at the middle of each surface being deeper than that near the pre- 

 hensile teeth. The teeth are of moderate size, irregular, the larger 

 ones alternating with one or two smaller ones ; at the broad proximal 

 end of the cutting edge there are 2 small teeth side by side, one near 

 the inner the other near the outer surface. 



This propodus differs from those of all the Recent Callinectes in 

 the position of the uppermost facet. In G. sapidus, etc., this facet is 

 a part of the outer series, that is, continues the slope of the adjoining 

 facet on the outer surface ; while in the fossil it inclines downward 

 toward the inner surface except at the distal end where it is nearly 

 horizontal. Furthermore, the propodus is shorter in proportion to 

 its height than in recent Callinectes. 



I have placed this species in Callinectes rather than in Portunus 

 (=Neptunu# of authors) because the palm is nearer the shape of 

 Callinectes than it is to similar segments in the genus Portunus, as 

 P. sanguinolentus ; the fossil is very unlike any Portunus now living 

 on the coast of tropical America. 



CALLINECTES RETICULATUS, new species. 



Plate 66, figs. 5-7. 



Type-locality. Panama Canal Zone. Las Cascadas section, Gail- 

 lard Cut. From lowest fossiliferous bed; third bed below lowest 

 limestone beds separated by rows of nodules. Lower part of upper 

 half of Culebra formation. Oligocene series. D. F. MacDonald 

 and T. W. Vaughan, collectors. 1911. Station 60200. Cat. No. 

 324261, U.S.N.M. 



Measurements. Greatest height of manus, 15.6 mm.; length of 

 manus measured horizontally on middle of outer surface, 19.2 mm. ; 

 thickness, 10 mm. 



