134 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Tribe ANOMURA. 



Super-family GALATHEIDEA. 



Family PORCELLANIDAE. 



PACHYCHELES LATUS, new species. 



Plate 57, figs. 21-23. 



Type-locality. Costa Rica; Port Limon. Pliocene series. Dr. 

 L. A. Wailes, collector. Station 4269. Holotype, left manus with 

 propodal finger; inner proximal corner of manus broken off. Para- 

 type, left manus, with both fingers; proximal portion of manus 

 broken off. 



Type. Cut No. 324264, U.S.N.M. 



Measurements. Width of palm, 4.6 mm. ; length of same to sinus, 

 5.1 mm. ; length to end of finger, 6.7 mm. ; greatest thickness, 2.3 mm. 



Holotype. Outer and inner margins thick and strongly curved 

 in dorsal view; upper surface covered with granules crowded to- 

 gether and of varying size ; the granules aTe continued on the outer 

 surface and a little way on the undor surface ; they are then replaced 

 by squamiform granules and short rugae which are continued over 

 the inner surface. There are no marginal lines indicated. At the 

 distal end, the width from the articulating condyle to the inner angle 

 is nearly as great as to the outer margin. The fixed finger is short 

 and stout, width subequal to length; a bit of the tip is, however, 

 missing; a low tooth occupies the greater part of the basal half of 

 the prehensile edge. 



Paratype. Smaller than the holotype and much worn so that the 

 granulation is not well marked. Tooth at base of immovable finger- 

 minute. Movable finger very short and broad, granulate, with a 

 basal prehensile tooth, its surface granulate. 



In general shape and granulation, this form resembles the manus 

 of the Recent P. grossi?nanus (Guerin) from Peru and Chile, but in 

 the latter the outer margin is paved with larger granules forming a 

 definite edge, and the propodal finger is longer and more curved. 



PETROLISTHES AVITUS, new species. 



1'late 57, ii^s. 18-20. 



Type-locality. Costa Rica : Port Limon. Pliocene series. Dr. 

 L. A. Wailes, collector. Station 4269. 



Type. Cat No. 324266, U.S.N.M. 



Holotype. Palm of left cheliped, showing the greater part of the 

 upper and lower surfaces including the inner margin and the distal 



