GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 153 



CALLIANASSA ?, species. 



Plate 64, fig. 10. 



Locality. — Panama Canal Zone. Las Cascadas section. From 

 lower part of lime-cemented soft gray to olive-colored limestone 

 (with central parting of dark clay). The first hard, limy sandstone 

 bed above the lower limestone just above station 60195. Upper part 

 of Culebra formation. Oligocene series. D. "F. MacDonald and 

 T. W. Vaughan, collectors. 1911. Station 6019c. Cat. No. 324280,. 

 U.S.N.M. 



Material. — One small specimen resembling in shape the merus 

 joint of the smaller of the chelipeds of the first pair. If the above 

 guess be correct, this is from the right cheliped. The two oblique 

 grooves near the distal end may have been artificially produced. 



Family PAGURIDAE. 



PETROCHIRUS BOUVIERI. new species. 



" Petrochirus cf. granulatus Olivier sp." Toula, Jahrb. der k. k. Geolog. 

 Reichsanstalt, Wien, vol. 61, 1911, p. 511 [25], pi. 30 [1], fig. 13. 



Gatun; Miocene (Toula). Not represented in the collection at 

 hand. 



There are two recent species of t 'etrochirus on opposite sides of 

 the continent, namely, P. bahamensis (Herbst) 1 =P. granulatus 

 (Olivier), which extends from Florida to Brazil, and P. calif omi- 

 ensis Bouvier 2 taken at La Paz, Mexico, and in Ecuador. One of 

 the principal differences between them lies in the ornamentation of 

 the chelae. The right chela of P. bahamensis is covered chiefly with 

 fan-shaped clusters of granules, all of which trend forward and 

 present a smooth, oval side-face when viewed dorsally; the clusters 

 vary in size, and some are composed of only 2 granules, while others 

 are represented by only one granule; all are fringed anteriorly with 

 hair, which fills the interspaces. The right chela of P. calif omiensis 

 has similarly clusters and single granules, but the clusters are not 

 fan-shaped but round, or nearly round, and are composed of a large 

 smooth central granule surrounded by small granules tipped with a 

 sharp, horny point; the granules are much more elevated and have a 

 more dorsal inclination than in bahamensis- the single granules are 

 also more numerous than in that species. 



The right chela of the fossil specimen figured by Toula resembles 

 that of P. calif omiensis. 



The left chela of P. bahamensis is covered with fan-shaped clusters 

 of granules like those on its right chela, but the clusters are more 



1 Cancer bahamensis Herbst, Naturg. d. Krabben u. Krebse, vol. 2, 1796, p. 30. 



2 Bull. Mus. Hist. Nat., Paris, 1895, p. 6. 



