1889.] NATURAL SCIENCES OF PHILADELPHIA. 277 



ON THE ANATOMY OF AEROPE AND ZINGIS. 

 BY H. A. PILSBRY. 



I am indebted to Mr. John Ponsonby of London, for alcoholic 

 specimens of a number of South African land-mollusks from which 

 the following anatomical notes are drawn. 



AEROPE Albers. 



The genus Aerope was founded on purely conchological characters 

 "by Albers and classed with the Helices, between Mierophysa and 

 Pella? 



Morch, in 1865, having dissected a specimen of the type and only 

 species of the genus, H. caffra Fer., placed it in the Agiiatha, 2 com- 

 menting upon the enormous size of the radula, with subulate, 

 elongated teeth disposed in converging lines. From an examination 

 of the animal of Helix knysnaensis of Pfeiffer, I am strongly inclined 

 to refer it to Aerope. My specimens having been in strong spirit 

 are much contracted, so that the following description is necessarilv 

 in) perfect. 



Aerope knysnaensis Pfr. (PI. ix. figs, a. b, c, i>). 



The shell is thin but strong, somewhat translucent, yellow, more 

 or less deeply tinged with green. Its surface is very bright and 

 polished, rather coarsely obliquely irregularly striate. There is 

 considerable variation in the contour of these shells, my figure d 

 representing an extremely elevated form. 3 



The foot (PL ix, figure j) is rather short, truncated anteriorly and a 

 trifle produced at the anterolateral angles. The sole is (in my con- 

 tracted specimens) transversely wrinkled, and although there is 

 no division into longitudinal tracts, the central part is lighter colored. 

 There are no furrows above the lateral margins, nor is there a pos- 

 terior mucous pore. The upper surface is coarsely granular. 



The buccal mass (PI. ix, fig. J, b.) is almost as long as the foot ; 

 longer than in any genus with which I am acquainted. The radula 

 is correspondingly elongated. The formula of teeth is about 27-1- 



1 Die Heliceen, 2d edition, p. S3. Type, H. caffra Fer. 



2 Journal de Conchyliologie, 1865, p. 395. Morch says : " J'ai eu occasion 

 d'examiner un animal desseche, dans lequel j'ai pu constater le presence d'un 

 appareil lingual relativement colossal, pourvu de dents subulees tres-longues, et 

 disposees en lignes convergentes." 



3 See Pfeififer's description, Monographia, i, p. S4. The figures in the 

 ' Concbylien Cabinet' are very unsatisfactory. 



