132 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Measurements. — Length of palm, 13 mm.; width, 4.3 mm.; thick- 

 ness, 3.7 mm. 



MACROBRACHIUM?, species. 



Plate 57, fig. 9. 



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. 324248, 

 U.S.N.M. 



Material. — One segment (perhaps the carpus) of the second or 

 large pair of chelipeds, probably the left one. Subcylindrical, en- 

 larging gradually to the distal end, slightly curved, a longitudinal 

 T-ow of 5 low conical spines irregularly spaced. 



Measurements. — Length, 9.5 mm. ; diameter, 1.7 mm. 



Suborder REPTANTIA. 



Tribe ASTACURA. 



Family HOMARIDAE. 



NEPHROPS COSTATUS, new species. 



Plate 57, figs. 13-17. 



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. 324246, U.S.N.M. 



Material. — Three dactyli of left cheliped, one of which is fairly 

 complete and is taken as the holotype; the other specimens show 

 only the distal half or two-thirds. A fourth specimen (distal half 

 only) represents a fixed finger perhaps and if so belongs on the left 

 side. 



Holotype. — Length 9.5 mm. In dorsal view the inner or right mar- 

 gin is sinuous, the tip curved strongly inward; viewed from the 

 inside, both edges are sinuous, curving downward toward the tip. 

 Upper and lower surfaces a little flattened. Five longitudinal 

 costae, 2 dorsal, 2 ventral, 1 inner; each costa marked by a line of 

 fine granules, with a row of punctae adjacent. On the proximal half 



