274 HAAS: ABIDA AND CHONDRENA. 



The name Pupa ringens Michaud, long in use for this 

 species, is unfortunately preoccupied by Pupa ringens Jef- 

 freys ; we substitute bigerrensis M.-T. for the Pyrenean form. 



I must make this species more comprehensive than Pilsbry 

 has done (Vol. XXIV, p. 278). Especially it seems to me 

 necessary to include within the range of its variation Pupa 

 baillensi Dup. and P. bigerrensis M.-T. (which Pilsbry con- 

 sidered respectively as a species and as a subspecies of 

 ringens) . 



Pilsbry has already shown (Vol. XXIV, pi. 43, figs. 12-15) 

 that A. bigerrensis {ringens) is rather variable in stature and 

 in the development of the aperture. The varieties elongata, 

 pulchella and disjuncta described by Moquin-Tandon repre- 

 sent only that many single stages in this range of variation, 

 and also Fagot's P. subringens gives no sufficient cause for 

 distinction. All of these forms Pilsbry has quite rightly 

 recognized as indistinguishable forms of ringens. In refer- 

 ence to P. bigerrensis M.-T. and P. bailie nsi Dupuy he could 

 come to no decisive judgment from the want of authentic 

 material, therefore treated these two as forms akin to ringens, 

 whereas I dare affirm their complete identity from my orig- 

 inal material. 



In the Rossmassler collection there are several P. bigerrensis 

 (under the name bigorriensis) , which came from Moquin- 

 Tandon, one of which is figured on pi. 23, figs. 11, 12. It 

 shows that bigerrensis altogether resembles the true ringens 

 except in the development of the peristome, which is not con- 

 tinuous and is but little thickened. From another collector I 

 possess further specimens from Bagneres-de-Bigorre, the type- 

 locality of P. bigerrensis, which differ in no respect from the 

 true ringens, even showing the continuous thickened peri- 

 stome accepted as characteristic of that species. 



Now, everyone who has collected pupillids often and at 

 various times of year, knows that full-grown specimens, with 

 the apertural folds of the species, can be found, in which the 

 peristome is not continuous, reflected or thickened. But a few 

 weeks later one can collect the same species at the same place 

 with completely continuous peristome; and not long after, 



