If G. crorikhitei cronkhitei is a valid western subspecies, it appears, 

 on the average, to be larger than anthonyi , and more elevated, to have more 

 rounded, and less carinate whorls, the aperture rounded and slightly 

 angled near the middle, the sculpture less sharp and heavy and more ir- 

 regular, the umbilicus averaging narrower, the colour often very dark, and 

 the surface usually more lustrous. 



Watson 1 has recently advanced evidence which would seem practically 

 conclusive in effecting the immediate removal of Pyramidula (as typified 

 by the European species rupestris Draparnaud) from the melange of forms 

 with which it generally has been associated, to a position in systematic 

 proximity to Vallonia, Acanthinula, and the Pupillidce. As not one of the 

 numerous American species which have commonly been referred here falls 

 under typical Pyramidula as thus newly defined, it is necessary 

 to align them with another group or else to elevate one or more of the sub- 

 genera containing them to full generic rank. The adoption of the latter 

 alternative in the present instance results in the rehabilitation of Gonyo- 

 discus Fitzinger, 1833. 



Proc. Malac., Soc. London, vol. 14, p. 6 and ff. 



