82 Trans. Acad. Sci. of St. Louis. 



49. Planorbis sampsoni Ancey. 



Pond, Flat Creek, Pettis Co., type lot (4); 

 Same place, May, 1883, (3) ; Same place, Aug., 

 1886, (25) ; Same place, July, 1889, (15) ; Flat 

 Creek, Pettis Co. (6) ; Bowsher's Spring, Mer- 

 cer Co. (3); Coelleda, Camden Co. (1). 



For some years this species was abundant in a pond 

 on Flat Creek near Sedalia, from which the type spec- 

 imens came, but when the locality of the pond was put 

 in cultivation the pond dried up and that locality was 

 exhausted. A few specimens have been found in Flat 

 Creek near by, a single one in Camden county, a larger 

 size in a spring in Mercer county, some at Athens, in Ill- 

 inois, and lately at one place in Arkansas. 



50. Planorbis exacuous Say. 



Pond, Flat Creek, Pettis Co. (68). 



This and the next were found in the same small pond 

 with Planorbis sampsoni. 



51. Planorbis parvus Say. 9 



Pond, Pettis Co. (21). 



52. Planorbis armigerus Say. 



Mouth of Wolf River (Hambach). 



Lymnjeid^. 



Lymn^in^. 



pseudosuccinea Baker 



51. Pseudosuccinea columella Say. 



Flat Creek, Pettis Co., 1881, (7) ; Lake, Moun- 

 tain Grove, Wright Co. (1); Pettis Co. (8); 

 Branch of Spring River, Carthage, Jasper Co. 



(1). 



