ART. 6 PORAMINIFERA: POLYMORPHINIDAE — CUSHMAN AND OZAWA 137 



named for Dr. M. Yokoyama, who described the fossil moUusks 

 from the same locality. 



Distribution. — Our specimens are from the upper Pliocene of 

 Sawane, island of Sado, and from Natsukawa, Province of Echigo, 

 Japan. 



SIGMOMORPHINA SAWANENSIS (Cushman and Ozawa) 



Plate 38, figures 1 a, b 



Sigmomorpha sawanensis Cushman and Ozawa, Jap. Journ. Geol. Geogr., 

 vol. 6, 1929, p. 74, pi. 16, fig. 6. 



Test ovate, greatest breadth just above the base, tapering toward 

 the apertural end; chambers numerous, elongate, about five times as 

 long as broad in the adult, each chamber reaching nearly to the base, 

 arranged in a contraclockwise sigmoid series; sutures distinct, slightly 

 depressed; wail of medium thickness, smooth, translucent; aperture 

 radiate. 



Measurement of the holotype specimen: Length 0.76 mm.; 

 breadth 0.33 mm. ; thickness 0.25 mm. 



This has a very much more elongate form than Sigmomorphina 

 sadoensis and is more involute than that species, the chambers being 

 very much longer and inclosing the earlier ones. It differs from the 

 European Sigmomorphina semitecta in its more broadly rounded base. 



Distribution. — The type specimens are from the upper Pliocene of 

 Sawane, island of Sado, Japan. We have additional specimens from 

 the upper Pliocene of Natsukawa, Province of Echigo, Japan. 



SIGMOMORPHINA VAUGHANI Cushman and Ozawa, new species 



Plate 38, figures 2 a-c 



Test almost rhombic with three rounded angles and acute apertural 

 angle, compressed, and more or less twisted, margin of the lower half, 

 wavy; chambers compressed, elongated, arranged in a clockwise 

 sigmoid series, each succeeding chamber farther removed from the 

 base; sutures slightly depressed, distinct; wall smooth; aperture 

 radiate. 



Length of holotype 0.80 mm.; breadth 0.62 mm.; thickness 0.30 

 mm. 



Holotype.— {C&t. No. 371262, U.S.N.M.) From the Eocene 

 (Cooper marl) at Ingleside marl pit, Charleston, S. C. (U. S. Geol. 

 Survey 6319). 



It differs from Sigmomorphina bornemanni from the German 

 Oligocene in its twisted test, wavy margins and more or less depressed 

 sutures. This species is named for Dr. T. Wayland Vaughan of the 

 Scripps Institution of Oceanography. 



Distribution. — Upper Eocene, United States, Cooper marl. In 

 addition to the type locality this species also occurs in the Cooper 



