392 THE CHICAGO ACADEMY OF SCIENCES. 



Planorbis deftectus. Bowmanville. 



Planorbis bicarinatus. Edgebrook, Avondale, Lincoln Park, 

 etc. 



Somatogyrus subglobosus. Lincoln Park. 



Valvata sincera. Maywood, Riverside and Salt Creek. 



p. 33. ECONOMY OF THE MOLLUSCA. Leucochila fallax SAY 

 has been found injurious to the strawberry, eating the stems 

 and crowns, rasping off the outer coating (epidermis) and suck- 

 ing the juices, thus causing the fruit to decay. Several thou- 

 sand specimens were picked from a patch of strawberries, and 

 forty specimens were found upon one plant.* 



p. 34. Under STATISTICS. No. 4. Comparison with Penn- 

 sylvania. Mr. Clapp writes the author that the number of spe- 

 cies quoted from Allegheny County, Pa., is much too small. Mr. 

 Clapp has very kindly forwarded a complete list of the Mol- 

 lusks of Allegheny County, and the figures on page 34 must be 

 changed to read as follows: families, 23; genera, 46; species, 

 131; varieties, 4. 



p. 54. Anodonta footiana is now considered a variety of 

 Anodonta grandis. 



p. 57. Alasmodonta rugosa Barnes should now be called 

 Symphynota costata Rafinesque (Ann. Gen. Sci. Brux., Vol. V, 

 p. 318, pi. Ixxxii, figs. 15, 16, 1820); vide Simpson. 



p. 58. Alasmodonta pressa should be called Symphynota com- 

 press a Lea. 



p. 60. Alasmodonta complanata should be called Symphynota 

 complanata. Alasmodonta should be changed to Alasmodonta, as 

 spelled by Say in Journ. Phil. Acad., Vol. I, p. 459, 1818. 



p. 62. Alasmodonta marginata Say should be changed to 

 Alasmidonta tnmcata, B. H. Wright. (See The Nautilus, Vol. 

 XI, p. 124, 1898.) The true marginata is confined to the Atlan- 

 tic drainage. 



p. 63. Alasmodonta deltoidea should be called Alasmidonta 

 calceola, the reference being Trans. Amer. Phil. Soc., Vol. Ill, 

 p. 265, pi. iii, fig. i, 1830. 



p. 71. Unio hildrethianus Lea should be changed to Hemi- 

 lastena ambigua Say. The genus Hemilastena (Agassiz, 1852) 

 Simpson, differs from Unio in the sculpture of the umbones 

 and in the teeth. The gills are united to the mantle posterior 

 to their ends. The name ambigua was used by Say in Journ. 



*Vide E. T. Cox, in the Amer. Nat., Vol. II, No. 12. p. 666, Feb., 1869. 



