166 NEW UNIONID^, MELAl^ID^, ETC., 



Eab. — Verdigris River, Kansas, F. Hawn, Civil Engineer. 



My cabinet. 

 Diam. -33, Length -67 inch. 



Remarlcs. — This is a well marked species near to Saffordii, herein described, and 

 belongs to the group of which Tieterostropha, Say, may be considered the type. It is 

 more straight than Tieterostropha, and not so much inflated as Saffordii, nor is it so 

 much polished. The half-dozen specimens before me are mature, but evidently dead 

 shells. There is no polish on them, but this may arise from want of perfection. In 

 all the specimens there is one or two bands of white callus marking the progress of 

 growth, and at each of these the suture above is indented. This is unusual with the 

 PJiyscB. The aperture is about two-thirds the length of the shell. I name the species 

 after Mr. Hawn, who collected it among other fresh-water shells on the Survey 

 through Kansas. 



■'c'- 



Phtsa Doebigniana. pi. 24, fig. 85. 



Testa late ovata, oblique inflata, late striata, subdiaphana, pertenui, colore columbse ; spira subobtusa ; 

 anfractibus quinis, convexiusculis, ultimo pergrandi ; apertura magna, late elliptica ; labro regulariter 

 expanso, subter marginem parum incrassato et dilute crocato ; columella medio impressa, parum in- 

 crassata et plica induta. 



Shell broadly oval, obhquely inflated, widely striate, semitransparent, very fragile, 

 dove color; spire rather obtuse; whorls five, the last very large; aperture very 

 large, broadly elliptical; outer lip regularly expanded, thickened and pale saffron 

 under the margin ; columella impressed and shghtly thickened in the middle and 

 furnished with a fold. 



P. Striata* Proc. Acad. Nat. Sci., 186-4, p. 115. 



Eab. — Salt Lagoon, near Monterey, Cal. J. B. Trask, M. D. 



My cabinet and cabinet of Dr. Trask. 

 Diam. -32, Length -55 inch. 



Remarks. — Dr. Trask sent to me quite a number of this species, interesting from 

 the fact of its inhabiting " water which is quite salt." I believe this is the first time 

 that the genus Physa has been found in other than perfectly fresh water. It is very 

 near in outline to Tieterostropha, Say, but it is a rather smaller, thinner species, not 

 quite so long in proportion, and the longitudinal striae distinguish it at once. These 

 striae are rather coarse and distant, and the whole surface of the whorls is covered 

 over with minute parallel strise. The aperture is about three-tenths the length of the 

 shell. 



*The name of striata being preoccupied by D'Orbigny (Moll. Cuba, v. 1, p. 192,) I substitute that of 

 Monsieur D'Orbigny. 



