4 CHONDRINA. 



was subjected locally to a great variety of conditions conse- 

 quent upon the elevation of the Alps and Pyrenees, with pro- 

 gressive interruption of limestone terranes by folding, fault- 

 ing and erosion. To these isolating factors, probably, the pro- 

 lific speciation is chiefly due. 



C. tingitana in Morocco is very closely related to forms of 

 the adjacent part of Spain. The group of C. goniostoma, pen- 

 chinatiana, letourneuxi and lallemantiana, reported from Al- 

 geria by Bourguignat and Letourneux, have an aspect so 

 Pyrenean that the possibility of importation occurs to one. 

 They appear out of place in Algeria. C. avenacea reported by 

 Letourneux also seems to be a stranger in Algeria, and Caziot 

 directly denies its occurrence there (Ann. Soc. Linn. Lyon, 

 Annee 1908, p. 160, footnote 1). 



Ch&ndrina is not certainly known anterior to the Pleisto- 

 cene. Several forms possibly referable to the genus are enu- 

 merated below, but by being toothless they resemble a few 

 aberrant terminal products of evolution in the recent fauna 

 rather than the more normal toothed forms which must have 

 been ancestral. There is little reason for referring any of 

 them to Chondrina, yet no other generic reference is obvious. 

 The absence of definite traces of this genus in known Tertiary 

 deposits leaves the question of its origin highly problematic. 



CHONDRINA(??) TROCHULUS (Sandb.). Pupa (Modicella) 

 trochulus SANDBERGER, Vorwelt, 1875, p. 601, pi. 29, f. 25. 

 CLESSIN, Malak. Bl. n. F., vii, p. 86. 



Upper Miocene : Morsingen, Undorf . Similar to Granopiipa 

 rupestris Ph. ; toothless ; but in view of the frequency of tooth 

 degeneration in Pupillida this character is almost worthless 

 as a test of relationship. 



PUPA MULTICOSTULATA Gutzwiller. Abhandl. Schweizer- 

 ischen palaont. Ges., vol. 32, 1905 (1906), p. 28, pi. 4, f. 30. 

 Eocene, Lausen near Basel. Aperture unknown, and position 

 doubtful ; externally resembles Chondrina. 



CHONDRINA(?) TOURNOUERI (Ancey). Pupa lusitanica 

 TOURNOUER, Journ. de Conchyl., vol. 27, 1879, p. 176, pi. 6, f. 

 3 ; not of Eossmaessler. Pupa tournoueri ANCEY, Le Natural- 

 iste, i, p. 414, n. 11. for lusitanica Tour. Pupa tournoueri 



