1895.] NATURAL SCIENCES OF PHILADELPHIA. 215 



Section first. No jaw ; only a chitinous, transparent membrane 

 covering the lips. Radula broad, oblong. Teeth of the radula very 

 numerous, en chevron, rows sloping obliquely backward ; the central 

 tooth long and slender, often obsolete; the laterals and marginals all 

 of the same type, base narrow, head rather broad, the denticles 

 varying in number from five to seven, in the last marginal from four 

 to two. 



To this section belong the following subgenera of Aehatinella, viz. : 

 Ichatinellastrum Pfr. ; Bulimella Pfr; Apex von Martens ; Ptatii- 

 lina Pfr.; Newcombia Pfr.; and Ebumella and Perdicella of Pease. 

 The species of these subgenera are all arboreal in their habit, and 

 their dentition is practically indistinguishable, except that in some 

 species the central tooth is absent or slightly varied. 



Section second. Jaw present; arcuate, strong, not ribbed. Radula 

 oblong, not wide. Teeth quadrate, in nearly straight rows; centrals 

 small, narrow, sometimes faintly tricuspid; laterals larger, bicuspid; 

 marginals bicuspid .or multicuspid. 



To this section belong the subgenera Amastra H. & A. Ad., and 

 Laminella Pfr. The species of the former are terrestrial, and those 

 of the latter either terrestrial or living on low shrubs. The differences 

 in the number of teeth are small, and the variations of shape trifling. 



It thus appears that in the majority of the generally accepted 

 subgenera of Aehatinella there is no possibility of separating the 

 sections by differences in the form of dentition. The terrestrial 

 species, or those tending to terrestrial habits, are characterized by 

 the presence of a jaw; the arboreal species, by its absence. The 

 group Amastra, including perhaps Laminella, are entitled to separate 

 generic rank. 



Section ACHATINELLASTRUM Pfeiffer. 



Aehatinella multizonata, n. sp. PI. X, figs. 1, 2. 



Shell dextral, imperforate, moderately solid, elongately conical, 

 apex subacute, surface shining, striated with fine lines of growth, 

 under a strong lens showing very numerous, extremely minute de- 

 cussating stria?; apical whorls smooth, scarcely decussated. Color 

 white, variously striped with numerous dark brown lines and bands, 

 some on the base and others spiral. Whorls 6, lightly marginate 

 above, convex ; suture lightly impressed. Aperture oblique, oval, 

 white, the dark bands of the exterior visible within ; peristome 



