148 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



CALLIANASSA HILLI, new species. 



I'lnte 58, figs. 18-20. 



Type-locality. — Gatun beds, Panama Canal Zone. Gatun forma- 

 tion. Miocene series. Robert T. Hill, collector; Station 18. 



Types.— Cat. No. 135218, U.S.N.M. 



Measurements. — Greatest height of carpus of right cheliped, 10.2 

 mm. ; superior length of same, 10.8 mm. 



Material.— 3 pieces of rock from the same place contain fragments 

 of Callianassa which belonged to at least 2 specimens and probably 

 represent a single species. The largest piece contains 2 fragments, 

 each consisting of a right merus and carpus (the better preserved of 

 these may be considered the holotype) ; the imprint of a right wrist 

 and hand; the distal half of a right propodus and a portion of the 

 dact,ylus. The second piece of rock has been broken from the first 

 and contains the continuation of the right propodus, with carpus 

 and merus attached (paratype a), also the first 1 segments of the 

 third right leg. The third piece of rock contains the sixth joint of the 

 tail (paratype b) . The following description is compiled from all 

 the specimens: 



The merus of the right cheliped has the outer margin prominently 

 carinate with a smooth rounded carina; upper margin granulated. 

 In both instances the merus is so flexed beneath the carpus that the 

 lower margin is not visible. The carpus is about equally long and 

 high ; its upper margin is slightly convex to a point near the articula- 

 tion with the merus; distal margin slightly concave, but nearly ver- 

 tical ; margin from the inf ero-distal angle to the merus strongly arcu- 

 ate. Manus about as long as high, moderately convex, outer surface 

 more so than inner; lower margin nearly straight; just above it on 

 inner surface a row of many fine punctae from which setae may have 

 sprung; this row is continued on the propodal finger; the latter is 

 only partly uncovered ; it is flat on the inner side, at least half as long 

 as the manus and its lower margin is a straight line continuous with 

 that of the manus. 



The right leg of the third pair is very much like the corresponding 

 member in C. stimpsoni Smith, the Callianassa of the Atlantic coast 

 of the United States. 



The sixth segment of abdomen or tail is subrhomboidal, with a con- 

 striction behind the middle; the segment is much wider in front 

 than behind ; the depressed portion at the anterior middle was hidden 

 in life under the fifth segment. 



CALLIANASSA VAUGHANI, new species. 



Plate 63, figs. 10-13. 

 Type-locality. — Panama Canal Zone. From 85-foot cut on north 

 side of big swamp on relocated line, Panama Railroad ; H to 2 miles 



