THE NAUTILUS. 95 



water, fall in upon themselves at the moment of low tide. They be- 

 come empty then by the rents in their exterior; but, in virtue of 

 their elasticity, they fill up again with air. At the return of the 

 tide, they thus form a float more than sufficient to raise up the oyster 

 that serves them as support. Therefore at each great tide, when the 

 beds are wholly uncovered, the oysters are seen to disappear in the 

 olfing upon this automobile algae. 



According to M. Bornet, we have the Colpomenia sinuosa, abound- 

 ing notably in the Mediterranean in the tracts adjacent to the At- 

 lantic. It was pointed out for the first time at Cadiz at the begin- 

 ning of the last century, and has never been seen farther north. It 

 no doubt came upon the hull of a vessel, and, having found in the 

 gulf of Morbihan suitable water, it multiplied there. 



Hitherto no other eflf'eciive means has been found of combating 

 this a'ga than to sweep the beds with prickly fagots. It is to be 

 hoped that a rigorous winter will be sufficient to cause it to dis- 

 appear. Scientific A mericun. 



BRITISH COLUMBIA SHELLS. Mr. Stewardson Brown, of the 

 Academy of Natural Sciences of Philadelphia, collected the follow- 

 ing species of land shells while on a botanical expedition in the 

 Canadian Rocky Mountains. At Field, B. C.: Tlnjsanophora in- 

 gersolli Bid., Vertigo goiddii Binn, Vertigo v. clulior Sierki, Vertigo 

 modestn Say, with the form parietalis Anc., Vitrea /tammonis Stiom, 



Vitrea binneyana Mse., Eucomd'is J'ldms Drap., Zonitoidcs ar'jorea 

 Say, Pyramidula c. anthonyi Pi Is., Splnjradium edentidum Drap., 

 Snccinea avara Say, and at Banff', Alberta : Vertigo modesta Say, 



Vitrea biimeynna Morse, JEuconulns fidcus Drap., Pyramidula c. 

 anthonyi Pils., Splnjradium edentalum Drap E. G. VANATTA. 



ADDITIONAL LOCALITIES FOR HELIX IIORTENSIS Since the 

 publication of my article on the distribution of Helix lioitensis in the 

 November NAUTILUS, I have received the following additional 

 records. From Curtain Island, Richmond Bay, Prince Edward 

 Island, a specimen of the plain yellow variety was received by Rev. 

 Henry AV. Winkley from a Mr. Ives. In 1902 Mr. Geo. H. Clapp 

 collected the banded variety (1234;")) at Cape Porpoise, about three 

 miles from Kennebunkport, Maine. Mr. Francis N. Balch has found 

 it at Orleans, Massachusetts, and also at Cohasset. 



