l66 JOURNAL OF CONCHOLOGY, VOL. 15, NO. 6, APRIL, I917. 



Others have in addition a deep-seated callosity on the columella, diffi- 

 cult to see from any point of view. 



x8 1 2 3 



/. triplicata Stud. /. ''^ triplicata." J. vmscorum L. 



Botzen, Tyrol. Brandon, Suffolk. Birkdale, Lanes. 



Spp. from the Chaster Collection in the National Museum of Wales, Cardiff. 



The three figures are all drawn from specimens in the Chaster 

 Collection at Cardiff. It will be seen from these that the last-whorl 

 characteristics in triplicata are, quite apart from the question of teeth, 

 of a distinctive nature. J. triplicata has a smaller and more oval 

 shell, deeper sutures, a proportionally smaller and more quadrangular 

 aperture, more convex whorls, teeth stronger and of a distinctly cal- 

 careous nature as opposed to the thin horny shell, and the exterior 

 rib of the aperture much less white and further from the margin. 



Anyone who is acquainted with this family knows that too much 

 reliance must not be placed on dentition. To show how inconstant 

 a character the tridentation is in /. triplicata, we may mention that 

 Westerlund has described var. edentula, var. iinidentata and var. 

 bidentata all from the South Tyrol ; the var. striatissa Gredler and 

 the var. inops Reinhardt are both bidentate forms, while the var. 

 luxurians Reinhardt has an extra palatal tooth. One of us has a 

 French example, ex coll. Crosse, with two strong parietals, one 

 columellar tooth, two palatals and one labial. 



Dr. Chaster emphasized (I.e., p. 320) a distinction between /. 

 muscorum and hisy! triplicata in the character of the parietal tooth. 

 The examination of his Brandon specimens shows that in some this 

 tooth has only the form of a " short ridge " or lamella, and in others, 

 that of a " minute rounded elevation." There cannot be any doubt 

 that this identification in 1906 was erroneous. The Brandon shells 

 are, in fact, a slightly variant race of y. tnuscoruui, probably peculiar 

 to the chalk warrens of Norfolk and Suffolk. We should, therefore, 

 doubt the reference to var. glis West., which was described from 

 Yorkshire examples. Unfortunately all trace of the type of this var. 

 seems lost. Mr. Ponsonby had no recollection as to what became 

 of it. 



