154 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



crowded, and single granules are fewer. The left chela of P. cali- 

 forniensis is covered with clusters like those on its right chela but 

 more crowded, and the granules of which they are composed are of 

 a smaller average size. 



The left chela of the fossil agrees more nearly with that of P. 

 bahamensis. 



We therefore have a Tertiary species combining the characters of 

 two Recent species, at least as far as the chelae are concerned, possess- 

 ing the right chela of one and the left chela of the other. 



Tribe BRACHYXJRA. 



Subtribe Dromiacea. 



Family DROMIIDAE. 

 Genus GONIOCHELE Bell. 



GONIOCHELE? ARMATA, new species. 



Plate 57, figs. 11 and 12. 



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

 lard Cut. From lowest fossiliferous bed. Third bed below lowest 

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

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

 and T. W. Vaughan, collectors. 1911. Station 6020a, Movable 

 finger of the left chelipecl. Cat. No. 324259, U.S.N.M. 



Measurements. — Length of movable finger (tip broken off) , 19 mm. ; 

 width at about the middle, 6 mm. ; greatest thickness, 4.5 mm. 



Hole-type. — The shape is elongate-triangular viewed from outside, 

 the prehensile edge being nearly straight and the upper edge slightly 

 arched; outer surface convex in both directions. The prehensile 

 edge has a sinus at its base, defined distally by a broad tooth which 

 is at present truncate, but may have been prolonged in two small 

 teeth ; beyond are four teeth separated by rounded sinuses and with 

 their tips missing: the first two are spiniform, the last two broad 

 and thin. The upper margin bears 5 low, spaced teeth, while just 

 within and alternating there is a line of 3 teeth. On the outer sur- 

 face are 2 rows of tubercles not far from the margins, 4 in the lower 

 and 3 in the upper row; the proximal tubercle in the upper row 

 is bifid. On the inner surface are 5 tubercles besides those above 

 mentioned, 2 in a longitudinal row in the middle, 2 on the distal half 

 a little above the prehensile edge, and 1 small one toward the top 

 and behind the middle. 



