THE NATURAL HISTORY SURVEY. 317 



GENUS APLEXA Fleming, 1828. 



Shell: Sinistral, narrow, elongated, thin, polished; spire 

 long; aperture narrow, long; peristome acute; columella lip 

 simple. 



Animal: With a rather long foot, rounded before and 

 pointed behind; mantle not reflected over the shell and with a 

 simple edge; tentacles long and slender, eyes at their bases; 

 genitalia?; jaw cartilaginous, arched, brown; radula with multi- 

 cuspid central tooth and comb-like lateral teeth resembling 

 those of Pkysa. 



Distribution: Europe, North America, Northern Asia, 

 Mediterranean region, West Indies, Oceanica.* 



129. Aplexa hypnorum Linne, pi. xxxii, fig. 16. 

 Bulla hypnorum LINNE, Syst. Nat., p. 1185. 

 Physa elongata SAY, Journ. Phil. Acad., Vol. II, p. 171, 1821. 

 Physaglabra DE KAY, N. Y. Moll., p. 80, pi. V. fig. 83, 1843. 

 Physa elongatina LEWIS, Proc. Bost. Soc. Nat. Hist., Vol. V, pp. 122, 



298, 1855. 



Physa turrita J. DE C. Sows., Fauna. Bor. Am.. Vol. Ill, p. 315. 

 Bulinus tyrant CURRIER, Amer. Journ. Conch., Vol. Ill, p. 112, pi. vi, 



fig. 2, 1867. (?) 



Shell: Very much elongated, thin, oblong; color yellow- 

 ish-horn, with sometimes a zigzag, longitudinal band of bright 

 yellow on the last whorl; apical whorls brownish, next black- 

 ish and last yellowish-horn; apex broadly round; surface pol- 

 ished, shining, diaphanous, growth lines numerous, but faint; 

 whorls six, somewhat regularly increasing, flat-sided, convex; 

 spire long, acutely conic; sutures but slightly impressed, mar- 

 gined; aperture elongate-ovate, narrow, contracted above, 

 somewhat rounded below and somewhat expanded, occupying 

 about half the length of the entire shell; peristome thin, sharp, 

 rounded, no callosity on the inside; columella narrowed near 

 the base, simple; no umbilicus; a view from the base of the 

 shell shows a perforation (through the aperture) from the base, 

 part way to apex. 



Length, 15.00; width, 6.00; aperture length, 8.00; width, 2.75 mill. (8507.) 



10.50; " 4.75; " " 5.50; " 2.25 " (8506.) 



15.00; " 7.00; " " 7.50; " 3.50 " (12314.) 



17.25; " 8.75; " " 8.50; " 3.50 " 



Animal: With a rather wide foot, rounded before and 



pointed behind; head prominent, separated from the foot by a 



*Tryon, S. and S. Conch., Vol. Ill, p. 103.' 



