[39] 



ascertained to be one of tlie few European species common 

 to both continents. It has been known among American 

 conchologists, until recently, as H. lucida, Drap., which, is, 

 however, a synonym of S. nitida, MiilL 



14. Hyalina arborea, Say. 



Plate 3, figure 17. 



Whorls 4|, regularly and moderately increasing, depressed 

 turbinate, thin, amber colored, smooth, shiaing ; lip slightly 

 flexuose ; umbilicus moderate and deep. 



Diam. 5 — 6 mill. C^'^l.V; Gc -'-, ' i'uct, ^ 



Georgia and northwards beyond Canada ; westwards to the 

 Eocky Mountains ; Los Angelos Co., California. 



15. Hyalina electrina, Gould. 



Plate 4, figure 25. 



Whorls 3|, depressed, pale, shining, the last rapidly en- 

 larging towards the mouth ; umbilicus very small, deep ; lip 

 not flexuous. 



Diam. 4 mill. Coll."^^a.■M:•.",Sr»<^i>^W3aa■k^':^e-vvY<h•W, 



Maine to Georgia, and westwards to Iowa. 



Differs from H. arborea in its pale color, more depressed, 

 smaller, fewer whorls, and their more rapid increase, and very 

 narrow umbilicus. _ " J^ iv^^rMno^pv. t^ -^ h^^^-^ '^"^ 



16. Hyalina^ ottonis, Pfeiffer. 



Plate 4, figure 26. 



Orbicularly depressed ; whorls 4, very light colored, nearly 

 white, suture narrow, periphery angular ; superior surface of 

 "whorls obliquely declining, inferior well rounded ; umbilicus 

 narrow and deep. 



Diam. 5, altitude 2*5 mill. 



Florida and West Indies. 



Much lighter colored and smaller than JT. arhorea, also 

 angled at the periphery and not so widely umbilicate. 



