GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 77 



POLYSTOMELLA CRATICULATA (Fichtel and Moll). 



Plate 27, figs. 3a, 6. 



Nautilus craticulatus Fichtel and Moll, Test. Micr., 1803, p. 51, pi. 5, tigs. 



h-k. 

 Polystomella craticulata d'Obbigny, Ann. Sci. Nat., vol. 7, 1826, p. 284, 



No. 3.— Caepenteb, Intr. Foram., 1862, p. 279, pi. 16, figs. 1, 2.— H. B. 



Beady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 739, pi. 110, figs. 



16, 17. 



Description. — Test bilaterally symmetrical, somewhat compressed; 

 peripheral margin broadly rounded; not lobulated, chambers very 

 numerous, forty or more in the last formed coil, narrow ; umbilical 

 region filled with clear shell material with numerous pores; bridged 

 area about equal to that between; aperture a series of openings at 

 the base of the apertural face. 



Diameter, 1 mm. Cat. No. 324692, U.SI.M. 



This species was found in considerable numbers in the Culebra 

 formation at U.S.G.S. No. 6025, in foraminiferal marl and coarse 

 sandstone about 200 yards south of the southern end of the switch at 

 Bohio Ridge station, relocated line, Panama Railroad. 



The specimens have not as subglobose a form as many recent 

 specimens, but in other respects the characters are very similar. 



POLYSTOMELLA, species? 



Numerous stations have a species of Polystomella which is very 

 much like P. sagra and yet is not so definitely characterized as are 

 the specimens of that species from station 6025. 



The stations at which this form of Polystomella occurs are in the 

 lower part of the Culebra formation at U.S.G.S. No. 6009, black 

 clays, six or seven hundred feet south of Miraflores Locks. In Las 

 Cascadas section, Gaillard Cut, 60196, from the 4 feet of dark strati- 

 fied tuff and clay overlying the lower limestone bed; 6019/, from 

 fourth limy bed from bottom; 6020a, from the lowest fossiliferous 

 bed. In the Emperador limestone at 6015 and 6016 from cream- 

 colored coral limestone, old quarry, one-quarter mile north of west 

 from Empire. In the Gatun formation at 6029&, from lowest hori- 

 zon, one-fourth to one-half mile north of Camp Cotton. 



Cat. Nos. 324693-8, U.S.N.M. 



Genus AMPHISTEGINA d'Orbigny, 1826. 



AMPHISTEGINA LESSONII d'Orbigny. 



Amphistegina lessonii d'Oebigny, Ann. Sci. Nat., vol. 7, 1826, p. 304, No. 3, 

 pi. 17, figs. 1-4; Modeles, No. 98.— H. B. Beady, Rep. Voy. Challenger, 

 Zoology, vol. 9, 1884, p. 740, pi. Ill, figs. 1-7. 



Description. — Test lenticular, usually more convex on one side than 

 the other ; composed of about twenty-five chambers in the last formed 



