GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 99 



sections, test of three or four whorls, walls of medium thickness, 

 the upright wall rather strongly recurved backward in the central 

 portion, 15 or 16 chambers in the last formed whorl. 



Occurrence. — Specimens were not common at station 6512 from 

 white limestone in river bed above ice plant near David, Panama, 

 collected by D. F. MacDonald. 



Type-specimen. — Cat. No. 324751, U.S.N.M. 



In material from station 6526 from Chiriqui, Canal Zone, col- 

 lected by MacDonald, numerous specimens occur which in section 

 seem identical with this species. 



Family MILIOLIDAE. 

 Genus ORBITOLITES. 



OEBITOLITES AMERICANA, new species. 

 Plate 43, figs. 12-14 ; plate 44, figs. 1, 2 ; plate 45. 



Test flat, of medium size, larger specimens about 10 millimeters 

 in diameter, chambers with the outer wall strongly convex, the inner 

 wall running backward and bluntly pointed, side walls parallel, 

 chambers in two or more tiers; tests mostly microspheric, one (pi. 43, 

 fig. 14) apparently megalospheric, and one (pi. 44, fig. 2) seemingly 

 originating from a fragment of an older test. Numerous specimens, 

 especially plate 45, figure 1, show evidence of breakage and repair. 

 The apertures between the chambers are not evident, as the material 

 largely consists of internal casts of the chambers. Some of the 

 specimens suggest the genus Presorites of the Cretaceous described 

 by Douville, but this is probably due to the condition of f ossilization. 



Occurrence. — Specimens which seem referable to this species are 

 from the following stations at Panama, collected by Vaughan and 

 MacDonald: Culebra formation, 6013, east side of Gaillard Cut; 

 60195, 6019-6-/, west side of Gaillard Cut near Las Cascadas; and 

 Q020a-c of the same section. Also collected in the Emperador lime- 

 stone at station 6015, in Empire. 



Type-specimen.— -Cat. No. 324748, U.S.N.M., from station 6020a. 



EXPLANATION OF PLATES. 



Plate 34. 



Lepidocyclina canellei Lemoine and Douvill6. 



Fig. 1. View of exterior of specimen X 10, a portion of a second specimen show- 

 ing above the first, from Bohio, Panama. (U.S.N.M. Cat. No. 135216.) 



