PUPILLA, EUROPE. 175 



Pupa- unidentata C. PFEIFFER, Syst. Anord. u. Beschreib. 

 deutscher Land- und Siisswasser-Schnecken, 1821, p. 58, pi. 3, 

 f. 19, 20. 



Pupa bidentata C. PFEIFFER, Syst. Anord. u. Beschreib. 

 deutscher Land- und Siisswasser-Schn., 1821, p. 59, pi. 3, f. 

 21, 22 (Schlosse zu Felsburg). 



Pupa marginata DRAPARNAUD, Tableau Moll. Fr., 1801, p. 

 58 ; Histoire, p. 61, pi. 3, f . 36-38. JEFFREYS, Brit. Conch., ii, 

 1862, p. 249, and of many European authors. 



Pupilla simplex LOCARD, Ann. d'Agricult. Lyon, (7), iii, 

 1896, p. 217; Conchyl. Fr., 1894, p. 329 (toothless form of 

 muscorum) . 



Pupa masclaryana PALADILHE, Nouv. Misc. Malac., i, 1866, 

 p. 11, pi. 1, f. 1-3. 



P. muscorum is characterized by the strong whitish crest, 

 the thickening within the lip, weak striation, and absence or, 

 when present, the small size of the parietal and lower palatal 

 teeth. There is usually no columellar tooth or nodule, but in 

 the Rocky Mountains a small columellar tooth is frequent, and 

 Boettger has noted its presence in a Marseilles specimen. 



Varieties according to the teeth. Shells having the typical 

 shape of muscorum (which varies, however, from short to 

 long in the same colonies) are classed by the number of 

 teeth, in three (or four) varieties, spread over the whole 

 European range of the species. 



1. Without teeth (pi. 20, fig. 1). This is the typical form 

 of muscorum; the name var. edentula Moq. used by many 

 authors and simplex of Locard are superfluous. It sometimes 

 occurs in pure colonies, more frequently associated with the 

 following. 



2. Having a short parietal but no other teeth (pi. 20, fig. 

 3 ) . The earliest name for this form is mut. marginata Drap. 

 It is generally called var. unidentata C. Pfr. The commonest 

 European form by far, often occurring with the preceding 

 and less commonly with the following forms. , 



3. Having short parietal and lower-palatal teeth (pi. 20, 

 fig. 7). This is mut. masclaryana Palad., which was based 

 upon an unusually short shell, pi. 20, figs. 16, 17. It has 



