98 PROCEEDINGS OF THE NATIONAL MUSEUM vol.77 



PSEUDOPOLYMORPHINA OKUWAENSIS Cushman and Ozawa 



Plate 25, figures 2, 3 



Pseudopolymorphina compressa d'Orbigny var. okuwaensis Cushman and 

 Ozawa, Jap. Journ. Geol. Geogr., vol. 6, 1929, p. 72, pi. 13^ fig. 7; pi. 15, 

 figs. 8, 9. 



Test compressed, elongated, rounded at the base, acute at the aper- 

 tural end, margin nearly parallel; chambers slightly compressed, as 

 long as wide, slightly embracing, arranged at first in a nearly triserial 

 series (the microspheric form) later becoming biserial; sutures gen- 

 erally slightly depressed, distinct; wall smooth, thick; aperture 

 radiate. 



Length 0.85-1.10 mm.; breadth 0.36-0.50 mm. ; thickness 0.15-0.27 

 mm. 



We formerly described this as a variety of Pseudopolymorphina 

 compressa, but it is very distinct from the latter in its much shorter 

 chambers. It may be compared with the European Pseudopoly- 

 morphina decora and American Eocene P. dumblei, with which it may 

 be closely related. Its distinction from these two is in the round 

 short chambers, but there are intermediate forms among the above 

 three species. 



Distribution. — It is quite abundant in the Japanese Pliocene as 

 well as now living in the same general region. 



Recent. — Kobama, Inland Sea of Japan, Province of Echizen, Japan. 



Upper Pliocene.— Ohuwsi, Province of Kaga, Japan. 



PSEUDOPOLYMORPHINA ISHIKAWAENSIS Cushman and Ozawa 



Plate 25, figures 4, 6 



Pseudopolymorphina ishikawaensis Cushman and Ozawa, Jap. Journ. Geol. 

 Geogr., vol. 6, 1929, p. 70, pi. 13, fig. 5; pi. 15, fig. 5 



Test much elongated, somewhat compressed, but the periphery 

 broadly rounded, sides in the adult portion nearly parallel; chambers 

 numerous, biserial, somewhat inflated, only slightly overlapping; 

 sutures somewhat limbate, not depressed, distinct; wall thick, smooth; 

 aperture radiate. 



Length 2.30-2.70 mm.; breadth 0.70-0.78 mm.; thickness 0^8- 

 0.52 mm. 



The elongate and narrow test consisting of oval chambers which 

 are arranged in an almost entirely biserial series will distinguish it 

 from any other species of the genus. 



Distribution. — The types of this species are from the Upper Plio- 

 cene of Okuwa, Province of Kaga, Japan. It also occurs in the upper 

 Pliocene of Natsukawa, Province of Echigo, and Dainichi, Province 

 of Totomi, Japan. The same species occurs in the Upper Miocene 

 of Kumonyo, Provmce of Totomi, Japan. 



