172 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



far as it is preserved accords with that of recent specimens; the 

 dactylus is more deflexed than it could be if the immovable finger 

 were preserved in situ. The tubercles of the palm are arranged 

 in general as in recent individuals, and slight divergences are attribu- 

 table to individual variation. The dactylus has 6 punctated grooves, 

 and the prehensile tooth situated at a little distance, from the base is 

 present; the three uppermost ridges bear some tubercles, the outer 

 ridge two tubercles, the upper one three tubercles, and the inner ridge 

 one tubercle followed by several crenulations. 



PANOPEUS ANTEPURPUREUS, new species. 



Plate 58, figs. 3-11. 



Type-locality. — Panama Canal Zone. From near Mount Hope in 

 ditch through swampy ground. About one-fourth mile from present 

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

 MacDonald, collector. April, 1911. Station 5850. 



Types.— Cat. No. 324245, U.S.N.M. 



Material. — 18 dactyli of stronger chela from right side; 9 dactyli 

 of stronger chela from left side ; 4 dactyli of weaker chela from left 

 side ; one propodal finger of weaker chela from right side. 



With one exception these digits belonged to small individuals ; the 

 exception, a right dactylus 12.8 mm. long, is made the holotype. 



The dactyli are very much like the corresponding parts of P. 

 purpureus Lockington, 1 a recent species ranging from Lower Cali- 

 fornia to Peru. The only differences are as follows : The fingers are 

 a little longer, slenderer, and straighter ; the large basal tooth of the 

 stronger chela is closer to the articulation with the manus ; there is no 

 coarse granulation on the basal portion of the dactyli, as there is on 

 the living form. Most of the specimens are purplish-blue except at 

 the tip. 



The propodal finger also is slenderer than in P. purpureus; the 

 lower groove of the outer surface is nearer the lower margin. As this 

 finger was not attached to a dactylus, one cannot be positive that it 

 belongs to the same species as the dactyli. 



PANOPEUS TRIDENTATUS, new species. 



Plate 58, figs. 12-15. 



Type-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. 

 MacDonald, collector. April, 1911. Station 5850. 



Types.— Cat. No. 324244, U.S.N.M. 



1 Proc. California Acad. Sci., vol. 7, 1876 (1877), p. 101. 



