588 



PR0CEED1NQ8 OF THE NATIONAL MUSEUM. 



vol. 49. 



PYRGULOPSIS OZARKENSIS, new species. 

 Plate 78, fig. 2. 



The shell is imperforate, corneal, smooth, whitish horn-colored; 

 whorls five, convex; the suture impressed. The aperture is holosto- 

 mate, oblique, widely ovate; columellar callus thick, the outer edge 

 slightly raised, and curved. The outer lip thickened, extending 

 beyond the outline of the spire. The type. Cat. No. 271765, 

 U.S.N.M., measures: Height, 3 mm.; diameter, 1.5 mm. 



Found in shallow water on the bedrock of the North Fork of White 

 River, 2 or 3 miles above Norfolk, Arkansas, on August 14, 1914. 



Differs from P. wabashensis in the convex whorls, deeper suture, 

 wider aperture, and the conical outhne. 



SOMATOGYRUS CRASSILABRIS, new species. 

 Plate 78, fig. 1. 



Shell small, depressed, translucent whitish horn-color, of about four 

 whorls; surface smooth but not polished, sculptured only with rather 

 sharp but not conspicuous incremental lines ; whorls rapidly increas- 

 ing in size, markedly flattened iji front of the suture, thence evenly 

 rounded; base rounded, with a minute but distinct umbihcus; aper- 

 ture obovate, the margin continuous, duplex, moderately and evenly 

 thickened; aperture bluish white within. The type, Cat. No. 271763, 

 U.S.N.M., measures: Height, 4.5 mm.; maximum diameter, 3.5 mm. 



Collected by A. A. Hinkley, in 1914, in North Fork of the White 

 River, at Norfolk, Arkansas. 



LIST OF SPECIES COLLECTED. 



G=collected at Galena, Missouri; C=collected at Cotter, Arkansas; N=collected at 

 Norfolk, Arkansas; B=collected at Black Rock, Arkansas; S=collected at Spring 

 River. 



Truncilla triquetra Rafinesque, C. 

 Lampsilis ventricosus Barnes, G. C. N. B. S 

 Lampsilis breviculus hrittsi Simpson, 



G. C. N. 

 Lavipsilis luteohis Lamai'ck, G. C. 

 Lampsilis ellipsiformis Conrad var., G. C. 

 Lampsilis ligamentinus Lamarck, C. B. S. 

 Lampsilis orhiculatus Hildreth, C. N. B. S. 

 Lavipsilis rectus Lamarck, G. C, N. 

 Lampsilis subrostrotus Say, G. 

 Lampsilis lienosus Conrad, N. 

 Lampsilis iris Lea, G. C. 

 Lampsilis glans, G. 

 Lampsilis purpuratus Lamarck, C. S. 

 Lampsilis gracilis Barnes, C. N. B. S. 

 Lampsilis leptodon Rafinesque, G. C. 

 Obovaria ellipsis I^ea, B. 

 Plagiola securis Lea, G. N. B. S. 

 Plagiola clegans Lea, C. N. B. 

 Plagiola donaciforviis Linnaeus, B. 



Tritogonia tu^erculata Barnes, C. N. B. S. 



Cyprogenia aberti Conrad, C. N. B. S. 

 Obliquaria rcflexa Rafinesque, B. S. 

 Ptychobranchus clintonensis Simpson, G. 



C.N. 

 Strophiius edenlulus Say, G. C. N. B. S. 

 Anodonta irnbecilis Say, G. 

 Anodonta suhorhiculata Say (pond), S. 

 Anodonta grandis Say. C. 

 Symphynota complanata Barnes, C. 

 Symphynota costata Rafinesque, G. C. N. 



B. S. 

 Alasmidonta calceola liCa, G. C. 

 Alasviidonta truncata B. H. Wright, G. C. 



N.B.S. 

 Unio gibbosus Barnes, G. C. N. B. S. 

 Plcurobevia utterbacki Fi'ierson, G. C. N. S. 

 Quadrula perplicata Conr&d, C. N. 

 Quadrula unaulata Barnes, G. B. S. 

 Quardula trapezoides Lea, B. 

 Quadrula q/hndrica Say, C. N. B. S. 

 Qiiadnda metanevra Rafinesque, B. S. 



