752 NOTES ON NORTH AMERICAN SHELLS STEARNS 



Succinea concordialia (louliL 



Six >s})c(;iiiieiis. 



Houina, La.; Venioii Bailey. 



This also is a well-dctiiicd and <'liara<*teristi(', torin, easily separable 

 from the pioccdiii!^ species, and lias lieietolbrc; beeu credited to "Lake 

 Concordia, in Texas." 



PlTLMONATA- 1 1 VcajOlMI ILA. 



Fiimily LIMN.EID^E. 



Genus PLANORBIS (iu.tiiinl. 



Plauorbis tumidiis Rtli(i( r. 



Numerous bleached si)ecimens. 



Pan Handle, Tex,, August 25, 181)2; Vernon Bailey. 



The shells of this species were ''found in a dry basin on the i>rairie, 

 at an altitude of 3,()t)0 feet above sea level." This form also occurs in 

 Nicaragua. 



Plauorbis tiivolvis Say. 



Ten examples. 



Houma, La.; Vernon Bailey, May, ISD'J, 



These shells are i)artly juniors, but (he lot contained a sufficient 

 number of perfect adults to admit of identilication. A common form 

 found nearly everywheie in North America. The National Museum 

 contains exam])les from Puebla, in the State of Puebla, and from Jalapa, 

 in the State of Vera Cruz, received fiom the Mexican Geographical 

 Commissiou a few years ago. 



Genus PHYSA Diapaniaud 

 Physa gyriiia Say. 



Numerous living examples. 



Stone County, Mo., Vernon Bailey, July 7, 1892. 



"Found in a creek near Marble Cave." 



Physa mexicana Philippi. 



Ten or more living specimens. 

 Houma, La. ; Vernon Bailey. 



These agree with the form to which Philippi gave the name luexi- 

 cana; it appears to be a very globose variety of heterontropha. 



SCUTIBRANCHIATA. 



Section UHI I'l IMHiLOSSA. 



Family HKLK INIDJ:. 



Genus HELICINA Lamarck. 



Helicina orbiculata Say. 



Numerous s])ecimens. 



Missouri, iu intone County, near Marble Cave; Vernon Bailey. 



