PLEKOCHEILUS-EURYTUS. 69 



Section EURYTUS Albers, 1850. 



Eurytm ALB., Die Hel., 1850, p. 169; Edit., 1860, p. 195, type 

 _B. pintadinus Orb. 



Shell ovate or elongated, varying from rather thin to solid and 

 either granulated, transversely striate or longitudinally rib striate. 

 Aperture exceeding half the alt. of shell ; peristome varying from 

 reflexed to simple and unexpanded ; columella with or without a 

 fold. Type Bulimus pintadinus Orb. 



The objection may reasonably be lodged against the above diagno- 

 sis that it is sufficiently loose to admit almost any Bulimus; but so 

 diverse are the elements of Ettrytus that no more exact definition 

 will cover all of them. At the same time, I am unwilling to split the 

 group into several new sections. It is always doubtful whether the 

 greater defmiteness of idea obtained by disintegrating such a group 

 as this into named sections, will recompense for the additional brain 

 burden of carrying the machinery of nomenclature. 



Key to groups of species. 



I. Shell solid ; lip reflexed ; columella with a strong fold above. 



Group of P. speciosus. 

 II. Shell thin, smooth ; columella with a lunate groove at root. 



Group of P. aulacostylus. 



III. Columella not strongly folded or grooved, 

 a. Lip well expanded or reflexed. 



b. Without creamy epidermal stripes, 



Group of P. coloratus. 

 bb. Epidermis with creamy, papery variegation, 



Group of P. mccinoides. 

 aa. Lip blunt, unexpanded or but slightly so. 



b. Ovate ; suture hardly descending in front, 



Group of P. castaneus. 

 bb. Ovate ; suture deeply descending in front, 



Group of P. taylorianus. 

 bbb. Elongated species, Group of P. floccosus. 



Group of P. speciosus; 



Ovate, smoothish, granulated or malleated. subperforate, solid ; 

 the peristome expanded and reflexed ; columella with a strong, 

 oblique fold above. 



