GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 137 



A a . Manas and carpus meeting in a vertical line Continued. 

 B 2 . Lower margin of manus directed straight forward or nearly so; ihat is, 



at right angles to its proximal margin. 



C*. Upper margin of manns snbparallel to lower margin. No tooth in 

 sinus between fingers. Carpus much higher than long. 



D 1 . Lower margin serrulate 911 o<f rate, p. 145 



D*. Lower margin granulate tonJai,p.l46 



C*. Upper margin of manus directed forward and downward toward lower 



margin. . 



D*. A large tooth in sinus between fingers and situated on base of im- 



*, P- 147 



0*. A small tooth in sinus between fingers, and situated near movable 

 finger. Carpus very little, if at all, higher than long __ JkiHi.p. 148 

 D*. No tooth in sinus between fingers. Fingers long and strong. 



B*. Lower margin of manns unknown. A stridulating ridge near the hori- 

 zontal upper margin __________________________ *f ridems, p. 151 



A*. Meeting of manus and carpus unknown. 



B 1 . Immovable finger slender. Distal articulating edge of manus crenulate 

 and very oblique -------------------------------- fra*3najui, p. 141 



B*. Only the dactylns known. 



C 1 . Dactylns of large sue. Cross section at base subcylindricaL Pre- 

 hensile edge thin ________________________________ magna, p. 151 



C*. Dactylns half as long as preceding, more compressed. Prehensile 

 edge thicker ----------------------- crassa, p. 152 



The 2 Callianassas to which specific names are not given are ex- 

 cluded from the above key. 



CALUAKASSA OVALIS, mew ijrriri 



Plate 59, figs. 1-4. 



Type-locaKty. Panama Canal Zone. Las Cascadas section. Grail- 

 lard Cot. From lowest fossilif erous bed, third bed below lowest 

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

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

 and T. W. Yaughan, collectors. 1911. Station 602Qa. Holotype 

 and one paratype. Cat. Ko. 324269, U.S.X.M. 



Holotype. A left chela with wrist and arm attached, and enclosed 

 in a nodule which is split in two. The specimen had been crushed, 

 and the half nodule containing the impression shows also small 

 pieces of the cheliped itself. Wrist and manus together oblong- 

 oval: line between them oblique; upper and lower margins of manus 

 slightly convex: greatest width about equal to the upper length; 

 from the widest point, the lower margin of the propodus slants 

 upward. Fingers directed straight forward and of subeqnal length. 

 Immovable finger an isosceles triangle, the base of which is two- 

 thirds as long as either side; end blunt; cutting edge with a shallow 

 triangular tooth at the proximal two-fifths. Movable finger sub- 

 oblong. end broad, cutting edge with a broad, shallow, rounded tooth 



