168 NEW UNIONID^, MELANIDiE, ETC., 



to microstoma, Hald., but there is no appearance of '■' teeth " on the columella. The 

 aperture is about seven-tenths the length of the shell. 



Phtsa Blandii. PL 24, fig. 88. 



Testa ovato-STibfusiformi, subobliqua, inflata, dilute straminea vel albida ; spira obtusa ; sutm-is impressis ; 

 anfraetibus quaternis, ultimo inflato et pergrandi; apertura ovata, subgrandi; labro expanse, subter 

 marginem incrassato et pallido crocato ; columella inerassata, impressa, plicata et contorta. 



Shell ovately fusiform, somewhat oblique, inflated, pale straw-color or whitish ; 

 spire obtuse ; sutures impressed ; whorls four, the last one inflated and very large ; 

 aperture ovate, rather large ; outer lip expanded, within the margin thickened and 

 pale salmon ; columella thickened, impressed, folded and twisted. 

 Proo. Acad. Nat. Sci., 1864, p. 116. 



5a&.— California, Mr. Thomas Bland. 



My cabinet and cabinet of Mr. Bland. 

 Diam. -30, Length -48 inch. 



BemarTcs. — Among a number of heterostropha, Say, sent to me by Mr. Bland, I 

 found the four specimens before me ; and I have great pleasure in naming it after 

 one who has done so much and so well for the terrestrial Mollusca of the United 

 States. It is a symmetrical, pretty little species, and nearly allied to Niagaremis, 

 herein described. The spire is'rather more produced and the substance of the shell 

 is rather thicker. The fold of the columella is not so well pronounced. All four 

 have a single thickened band within the edge of the margin. The texture of the 

 shell is porcelainic. The aperture is about five-sevenths the length of the shell. 



Phtsa ventjsta. PI. 24, fig. 89. 



Testa subcjlindracea, tenuissima, diapbana, nitida, alba; spira curta, acuminata; suturis leviter impressis; 

 anfraetibus quaternis, convexiusculis, ultimo pergrandi ; apertura magna, elongato-ovata, subter mar- 

 ginem fusca; labro acuto et sinuoso, vix expanse; columella parum impressa. 



Shell subcylindrical, very thin, transparent, shining, white ; spire short, pointed; 

 sutures slightly impressed ; whorls four, slightly convex, the last one very large ; 

 aperture large, elongately ovate, under the margin brownish ; outer lip acute, sinuous 

 and slightly expanded ; columella slightly impressed. 

 Proe. Acad. Nat. Sci. 1864, p. 116. 



Hob. — Near Fort Vancouver, Oregon, Sir George Simpson. 



My cabinet and cabinet of Lady Catherine Douglas. 

 Diam. -26, Length -55 inch, 



Bemarlcs. — I have before me three specimens of this graceful, delicate species, 

 which was taken by Sir George Simpson many years since, and kindly sent to me by 



