NO. 4 CUSHMAN AND MCCULLOCH : SOME VIRGULININAE 193 



very slightly tapering, somewhat contracted toward the apertural end, 

 which distinctly projects; chambers distinct, slightly inflated, high, 

 strongly overlapping, except the last three chambers; sutures distinct, 

 slightly limbate, very slightly depressed, somewhat sigmoid, forming a 

 slight angle with the horizontal, the inner margin with a distinct lobe; 

 wall finely but distinctly perforate, with a tendency for the upper portion 

 of the chamber to become clear; aperture large, broad, with a distinct, 

 raised lip. Length 0.70-0.80 mm. ; breadth 0.25-0.28 mm. ; thickness 0.15- 

 0.18 mm. 



The types are from the Miocene, 2,040 feet stratigraphically above 

 base of Modelo formation as exposed along road from Girard to Mohn 

 Spring, Santa Monica Mountains, California. 



Numerous specimens from restricted areas off the coast of Mexico 

 seem to be identical with the types of this species. 



Stations: 57, 59, 60, 62, 67, 2100. 



In some specimens there is a tendency toward a lobing of the sutures 

 similar to that seen in Bolivina sinuata Galloway and Wissler, but the 

 early stages are not the same. This is shown in our figured specimen. 



Distribution. — All of these station records are off the tip of Lower 

 California, Mexico, beginning with the Santa Maria Bay on the Pacific 

 side, in 7 fms., and around Cape San Lucas to the region of Espiritu Santo 

 in 150 fms. 



Bolivina imbricata Cushman 

 Plate 23, Fig. 8 



Bolivina imbricata Cushman, Contr. Cushman Lab. Foram. Res., vol. 

 1, pt. 2, 1925, p. 31, pi. 5, figs, la, b; vol. 2, pt. 3, 1926, p. 54. — Cushman, 

 Stewart and Stewart, Trans. San Diego Soc. Nat. Hist., vol. 6, 1930, p. 

 68, pi. 8, fig. 3. — Cushman, Special Publ. 9, Cushman Lab. Foram. Res., 

 1937, p. 99, pi. 10, fig. 23. 



Test elongate, about 2^/^ times as long as broad, very strongly com- 

 pressed, periphery acute and keeled throughout; chambers distinct, early 

 ones much broader than high, gradually increasing in relative height in 

 the adult portion, strongly overlapping; sutures distinct, strongly limbate, 

 much curved; wall thin, finely perforate, the surface ornamented with 

 strong longitudinal costae, 8 to 10 on each side, the central one strongest 

 and often continuing nearly to the apertural end of the test, the others less 

 prominent, and usually limited to the first third of the test; aperture 



