14 THE NAUTILUS. 



the genus Vitrea Fitz. On the other hand, as well known, our 

 Mesomphix (s. str.) are hardly to be separated generically from Hija- 

 linia {Euhyalinia), as glabra, draparnaldi, cellaria, etc., and forms 

 like our tvheatleyi, petrophila from pura, etc., not to speak of radia- 

 tida which is equally distributed on the old and new continents. 

 We may, for all these, use the generic name Hyalinia, the more 

 since such authorities as W. G. Binney, Tryon and others have done 

 so before, and no embarrassing of the synonymy will result. Yet all 

 these forms still need careful examination as to their anatomy. 



2. Some Zon. suppressus Say, show not a trace of internal teeth or 

 rather lamellse, when adult ; W. G. Binney (1. c. p. 226) also says 

 that the tooth is sometimes " so little prominent as to be hardly 

 visible." I have in possession specimens from Ohio and Virginia 

 (Petersburgh, collected by myself) of 7-8 mill. diam. and 7-7^ 

 whorls, with the last whorl and aperture well-rounded, without any 

 " teeth," and only a thin callus inside. As to size and shape, they 

 differ essentially from W. G. Binney's description and figure." With 

 these, there were examples of all ages and sizes, inseparately con- 

 nected' with the former, having two strong lamellae upon a heavy 

 callus. Also in gularis and other forms of the group, the lamellse 

 considerably decrease in size and number with advancing age, and 

 at maturity sometimes are quite short and thin. 



3. Mrs. Geo. Andrews, to whom we owe so many valuable finds 

 among land mollusca, sent me, in 1891, a number of " Zonites gularis 

 small var." Then I was satisfied that they were not gidaris ; and 

 now, after repeated comparison and examination also of the soft 

 parts on specimens recently obtained, this is beyond a doubt, and as 

 well, that it is a distinct species, not yet described. Here only so 

 much of the description will be given as to serve our purpose. The 

 shell is of the general appearance of a small Z. ligeriLS, of only 9 

 mill, greater diameter, finely perforated, with a high spire, well- 

 rounded at the apex. Inside there is a rather long fold correspond- 

 ing to the same (outer) in Z. gularis, etc., and a lower one near the 

 columella. In a part of the specimens there is another (outer) long 

 fold, about 2-1 volution above the aperture, sometimes connected 

 by a fine marking with the one in front ; evidently this is the one 

 previously formed and not resorbed, the same thing as in Z. internus, 

 etc. 



4. A few examples of Zonites, I| think a form of demissus, from 



^ Manual, p. 225 ; fig. 241, looks like drawn from an immature specimen. 



