174 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



is much worn, but there is a line of punctae visible through the mid- 

 dle; there is a large subbasal tooth directed obliquely backward, and 

 bounded posteriorly by a deep, wide groove ; the tooth does not pro- 

 ject beyond the general lower margin, but it may have done so when 

 entire. On the distal portion of the outer edge of the prehensile sur- 

 face there are a few shallow crenulations. 



This specimen comes nearer to Panopeus than to any other known 

 genus; from P. cMe-nsis Milne Edwards and Lucas 1 it differs in 

 its greater width, in the large tooth originating higher up on the 

 outer surface and in the groove behind it being deeper and more 

 extensive. 



EURYTIUM CRENULATUM, new species. 



Plate 64, figs. 8 and 9. 



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

 ditch through swampy ground. About one-quarter mile from pres- 

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

 MacDonald, collector. April, 1911. Station 5850. 



Holotype.Cat. No. 324253, U.S.N.M. Dactylus of right chela, 7.6 

 mm. long. This has the general shape of a Eurythim finger, but the 

 large basal tooth of the prehensile edge is inserted higher up, its 

 oblique base running posteriorly well up on the outer surface; the 

 tooth is directed strongly backward and is broadly rounded at the 

 extremity. It is followed by about ten low teeth, the first and third 

 of which are the larger. Somewhat above the middle of the inner 

 .and of the outer surface there is a longitudinal depression containing 

 a row of a few punctae. There is a deep groove on the upper sur- 

 face and just within it but higher up there is a row of separated 

 granules or crenulations; they point outward, that is, a side view of 

 them may be obtained by looking down on the top of the finger. 

 The ridge just outside the dorsal groove is proximally microscopically 

 granulate. 



This finger can not be referred to E. affine 2 or E. tristani 3 of the 

 Panamian fauna on account of the elevation and direction of the 

 basal tooth, and the row of granules on the upper edge. 



Family GONEPLACIDAE. 



Subfamily PRIONOPLACINAE. 



EURYPLAX CULEBRENSIS, new species. 



Plate 66, figs. 13 and 14. 



Type-locality. Panama Canal Zone. Top part of limy sandstone 

 below upper conglomerate, near foot of stairs, Gaillard Cut. Upper 



1 D'Orbigny's Voy. Am6r. M6r., vol. 6, pt. 1. 1843, p. 16 ; vol. 9, atlas, 1847, pi. 8, fig. 2. 

 a Panopeus affinis Streets and Kingsley, Bull. Essex Inst, vol. 9, 1877, p. 106. 

 Rathbun, Proc. Biol. Soc. Washington, vol. 19, 1906, p. 100. 



