148 THE CHICAGO ACADEMY OF SCIENCES. 



tivity, taking a long time to come from its shell, even when 

 immersed in water for a considerable time. When extended it 

 will retract at the slightest jar. It does not readily crawl about, 

 as do many of the smaller species of Polygyra, but rests 

 half extended from its shell, twists its head about, raises its 

 body high in the air, and constantly feels about with its eye- 

 peduncles and tentacles. This species is found in the southern 

 and western regions. 



My friend, Mr. George H. Clapp of Pittsburg, Pennsylva- 

 nia, has questioned the propriety of changing this well-known 

 name and has offered very weighty reasons for the rejection of 

 fraudulenta. With a view to prove or disprove the validity of 

 the change I hunted up all the references to this species in 

 American works (Tryon, the two Binney's, Pilsbry, etc.), and also 

 carefully read the original descriptions of Say. After a care- 

 ful perusal of these, and a comparison of numerous specimens, 

 I am of the opinion that the change is valid, although Say's 

 description is rather ambiguous. I believe the curved parietal 

 tooth refers to introferens rather than to fallax. It is my opin- 

 ion that Say had before him specimens of both fallax and intro- 

 ferens, and that he intended his type to be the %ntrofertns-\Sk& 

 shell. It may be remarked, however, that the truth of the 

 matter is that without the actual type, which is not now in ex- 

 istence, nothing can be definitely settled concerning what Say 

 really meant by his description, as it will fit pretty well both 

 fallax and introferens. 



54. Polygyra profunda Say, pi. xxix, figs. 8, 10, 11. 



Helix profunda SAY, Journ. Phil. Acad., Vol. II., p. 160, 1821. 



Helix richardi FERUSSAC, Tab. Syst., p. 43; Hist., pi. Ixx (three lower 

 figures). 



Helix biilbina DESHAYES, in Ferussac Hist., Vol. I, p. 108, pi. lxxxv > 

 figs. 14-18. (Junior?) 



Polygyra profunda alba WALKER. Terr. Moll. Mich., p. 12, 1899 (va- 

 riety). 



Shell: Depressed, rather solid, widely umbilicated; sur- 

 face covered with numerous coarse, oblique, rib-like growth 

 lines which are crossed by numerous very fine spiral lines; 

 nucleus without markings; periphery rounded; sutures deeply 

 impressed; color yellowish horn, with one well-defined brown 

 band above the periphery, and one wide or two narrow fainter 

 bands below the periphery; the shell may also be uniform horn- 

 color, brown, albino, or there may be a peripheral wide band 



