20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



Test small, globular ; diameter up to about 14 mm : surface marked 

 by an irregular network of raised cbamber walls. 



A horizontal section through the medium plane of a specimen hav- 

 ing a diameter of 1.4 mm (pi. 2, fig. 3) shows that the chambers 

 in the test are irregularly polygonal in shape, having a diameter of 

 from 40 to 60 fi. At a point about 240 /x from the center, the 

 chambers become regular in shape and are arranged in definite 

 radial rows, the chambers being short rectangular, the tangential 

 diameter exceeding the radial diameter. The dimensions of the 

 chambers increase toward the periphery of the test ; at a point about 

 240 /A from the center, radial diameter about 40 fi ; tangential diam- 

 eter about 50 ju, ; at a point 700 fi from the center, radial diameter 

 about 45 JU. ; tangential diameter about 60 /x. Chamber walls are about 

 18 fi thick; roofs and floors of chambers perforated by cribriform 

 perforations having a diameter of about 4 fi. 



Localities and geologic Jioricon. — Thin sections of material from 

 localities 4, 469, 960, iii/, 1123, 1208, and 1209 contain a few speci- 

 mens that resemble this species too closely to be referred to any other. 



All the localities listed are in the San Luis series, which is con- 

 sidered middle Oligocene. 



GYPSINA VESICULARIS (Parker and Jones) 



Plate 2, figs. 4. 5 



Orbitolina vesicularis Parker and Jones (36, p. 31, no. 5). 

 Tinoporus vesicularis Brady (6. p. 718, pi. lOi, figs. 9-12). 

 Gypsina vesicularis Cushman (14, p. 43). 



A few specimens apparently belonging to this species were found 

 in material from localities 149 and 163. 



Diameter of test i to 3 mm; thickness from about 0.3 to 0.7 mm; 

 smaller specimens disk-shaped ; larger ones curved and wavy, attached 

 side concave. Surface entirely covered by areolae, which have a 

 fairly constant size, about 39 to 50 /x, but are very irregular in form. 

 Vertical section of a specimen from locality 149 (pi. 2, fig. 4) has a 

 diameter of about 2 mm, thickness about 0.5 mm. 



This species is associated with D. {Asterocyclina) asterisca 

 (Guppy). D. {Asterocyclina) kugleri Gravell, n. sp., L. (Lepido- 

 cyclina) trinitatis H. Douville, and L. (Lepidocyclina) macdonaldi 

 Cushman. 



Although this species has no stratigraphic value, the associated 

 species indicate that the horizon is upper Eocene. 



