THE NAUTILUS. 

 NOTES. 



SAN DIEGO DRIFT SHELLS. A small bag of drift taken on 

 the shore of False Bay, near Asher Station, San Diego, Califor- 

 nia, March 28, 1916, contained the following interesting assem- 

 blage of molluscan shells, Mr. E. G. Vanatta being responsible 

 tor certain of the determinations. 



Pisidium species. 



Assiminea californica Cooper, one specimen (E. G. V.). 



Lymnaea bulimoides Lea, young. 



Physa niMalli Lea, young (E. G. V.). 



Planorbis deflectus Say, two young specimens (E. G. V.). 

 This species seem to be new to Southern California. 



Succinea stretchiana Bland, young (E. G. V. ). 



Vitrea shepardi (Hemphill), one specimen (E. G. V.). 

 Recorded heretofore from Santa Catalina Island. 



Striatura milium pugetensis (Dall). 



Striatura milium meridionalis (Pilsbry and Ferriss), one speci- 

 men (E. G. V.). 



Punctual conspectum (Bland), the most common species. 



Vertigo diegensis Sterki, one specimen. 



Bifidaria hemphilli Sterki. S. S. BERRY. 



ANTIQUITY OF THE HELICES. Helix (Epiphragmoph&ra) tudicu- 

 lata is a land snail peculiar to Central and Southern California, 

 ranging from the Sierras southward to San Diego. It is very 

 common, and even abundant in some localities. 



A few years ago the writer found a fossil specimen of this 

 species in Silverado Canyon, Santa Ana Mountains. Orange 

 County, California, which cannot be assigned to a later period 

 that the Miocene, and may be even older, as the Eocene and 

 Cretaceous are also known to occur in Silverado Canyon. 



The shell was found in situ, being embedded in a ledge of 

 rather soft limestone, which contained numerous fossil leaves 

 and stems. It was remarkably well preserved, retaining much 

 of its original color, and the dark band encircling the larger 

 whorl was still very distinct. 



The writer is not aware that the species tudiculata has ever 

 before been reported as being identified with any geologic 

 period. E. E. HADLEY. 



NOTE ON VALVATA MICRA Pils. and Ferr. When this species 

 was described ' I doubted its pertinence to Valvata, suggesting 

 that it might be a Horatia or Daudebardiella. I have recently 

 seen an article by C. Pollonera, 2 in which he described a sub- 



l Proc. A. N. S. Phila. 1906, p. 172. New Braunfels, Texas. 

 8 Bolletino dei Musei de Zoolo^ia ed Anatomia Comparata della R. Univ. 

 di Torino, Vol. xiii, No. 334, p. 3, Dec., 1898. 



