

MANUAL OF CONCHOLOGY. 



Family OLEACINIDJE. 



Most systematic writers on land snails, including Pfeiffer 

 (Nomenclaton Heliceorum Viventium, 1878), have placed 

 Spiraxis, Melaniella and the slender species of Varicella 

 among or adjacent to the Stenogyrodd Achatinidce. Their 

 true position proves to foe in the family Oleacinidce, which 

 was monographed by Mr. Tryon in Vol. I of this series. 

 Since species of these groups will naturally 'be looked for 

 among the Stenogyroid groups, it has been thought best to 

 insert them here. The opportunity has been taken to revise 

 the 'classification of the Oleacinidcz and to supplement the 

 account in Vol. I by illustrations and descriptions of new 

 forms and of others ^published since the appearance of that 

 volume, without duplicating matter contained therein. 



Genus PSEUDOSUBULINA Strebel. 



Pseudosiibulina STREBEL, Beitrag Mex. Land und Siisswasser 

 Conchyl. v, p. 117 (1882). v. MARTENS, Biologia Centrali 

 Americana, Mollusca, p. 301. TRYON, Manual of Conchology, 

 2d. Series, i, p. 50. 



The shell is slender and turrite, pale and subtransparent, 

 closely resembling that o'f Subulina; but with fine rib-sculp- 

 ture. Columella usually more or, less distinctly truncate at 

 the base. Apical whorl smooth. 



The jaw is represented by a slight crescentic thickening of 

 the epithelium, distinct on its lower border, but passing in- 

 sensibly into the general integument at the sides and above. 

 It is composed of narrow plates. 



The radula is Oleacinoid, the teeth arranged in V-shaped 

 rows. Central tooth rudimentary, .with a small cusp. The 



