﻿GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 93 



are a few larger than the others; embrA'onic chambers of the double 

 type, the two chambers nearh' equal in size and separated by a 

 straight common wall. 



Horizontal section shows similar conditions of the embryonic 

 chambers and distinctly hexagonal equai^^orial chambers, 



OccuiTence. — Lemoine and Douville described this species from 

 Panama (Haut-chagres, San Juan). The figured specimens are from 

 United States Geological Survey station 6025, Culebra formation, 

 from marl, south end of Bohio Ridge switch, relocated line, Panama 

 Railroad, collected by Vaughan and MacDonald. 



Specimens from station 6019-/, Culebra formation, on the west 

 side of Gaillard Cut near Las Cascadas, seem to represent the micro- 

 spheric form of this species. The sections are show^n in plate 35, 

 figure 3, and plate 36. 



A specimen from station 6526, Chiriqui, Canal Zone, shows a sec 

 tion which from its general proportions strongly suggests L. chapeii. 



Cat. Xos. 324736-8, U.S.N.M. 



LEPIDOCYCLINA VAUGHANI. new species. 



Plate 37, M^'s. 1-5 ; plate 38. 



Test of medium size, 10 millimeters or more in diameter, flat, sur- 

 face somewhat umbonate in the central portion, gradually sloping to 

 the peripheral i^ortion, the outer half of which is nearly flat. Wall 

 smooth except for fine papillae. 



Horizontal section shows the peculiarity of the chambers, man}' of 

 which, esj)ecially those of the outer peripheral portion are rhomboid, 

 those of the inner portion being more typical and hexagonal. These 

 are shown especially well on the sections of the larger specimens, 

 those of the smaller specimens showing only the regular hexagona' 

 character of the earlier chambers. 



No very good vertical sections were obtained in the thin sections 

 but several accidental sections show the characters well. The em- 

 bryonic chambers are rather large, of the usual American type, of 

 two nearly equal chambers, lateral chambers in vertical columns 

 with a very few, rather well developed pillars. 



Occurrence. — Type-specimen from station 6021, from the Empera- 

 dor Limestone in cuttings of the Panama Railroad near Caimito 

 Junction, Panama, United States National Museum Catalogue No. 

 324739, collected by T. W. Vaughan and D. F. Mac Donald. Speci- 

 mens were abundant in this light gray to cream-colored sandy lime- 

 stone. Specimens were also abundant in the collection from the same 

 locality collected later by MacDonald under station No. 6673. Speci- 

 mens which are apparently the same species are abundant in a fos- 



