24 PROCEEDINGS OF THE ACADEMY OF [1896. 



This species is described from four specimens collected by Gabb 

 (the types), and one in the collection of Mr. John Ponsonby, of 

 London. The latter is slightly larger, and, at first glance, seems to 

 have the aperture more vertical, but this is caused by the breaking 

 away of the upper portion of the lip-edge. 



The columellar callus becomes a little heavier, slightly convex, 

 toward the lower end of columella. Upon breaking a specimen a 

 minute embryonic shell was found. The species is therefore prob- 

 ably viviparous, as I have shown some other species of Thysanophora 

 and Sagda to be. The callous lining of the interior in the columellar 

 region is conspicuous in this species but absent in H. effusa Pfr. 

 Both species seem to me referable to Sagda rather than to Thysano- 

 phora; but the two genera are intimately allied. 



