8 CHONDRIN.E OF THE ALPIC CENTER. 



very small, upper and lower palatals long, the former emerg- 

 ing to the peristome, basal plica small, rather deep. Peri- 

 stome is expanded and strongly thickened within, white. 



Length 7, diam. 3 mm.; 7% whorls (Como). 



Length 8, diam. 3.2 mm.; 8 whorls (Como). 



Length 10.3, diam. 4 mm.; 9 whorls (Milan). 



Italy: Lombardy and Piedmont; also in adjacent parts of 

 the Tyrol and Switzerland, and rare west to Grasse (Alpes- 

 Maritimes) ; valley of the Verdon, Basses- Alpes, abundant 

 and of good size (Margier). 



Chondrus megacheilos DE CRISTOFORIS et JAN, Catalogus 

 rerum nat. in Museo extantium Joseph! de Cristof ori et Georgii 

 Jan, sect, ii, pars 1, fasc. 1, p. 5, Mantissa, etc., 1832, p. 3. 

 Pupa megacheilos Jan, ROSSM., pt. 5, 1837, p. 13, pi. 23, f . 318 ; 

 iii, pt. 17, p. 106, pi. 85, f. 938. KUESTER, Conchyl. Cab., p. 

 46, pi. 6, f. 6-8. DBS MOULINS, Actes Soc. Linn. Bord., vii, 

 1835, p. 162, pi. 2, f. Al, A2. MOQ.-TAND., in part, Moll. Fr., 

 p. 354, pi. 25, f . 23-32 ; with var. rufula. PFR., Monogr., ii, 

 346; iii, 547; iv, 673; vi, 315; viii, 384 (see for older refer- 

 ences). WESTERLUND, Malak. Bl., xxii, 1874, p. 62 (new 

 diagnosis, and notes on transitions to avenacea) . SCHROEDER, 

 Nachrbl. d. m. Ges., vol. 45, 1913, p. 171 (varieties, etc.). 

 E. MARGIER, Feuille Jeunes Naturalistes, 1904, no. 399, p. 65. 

 CAZIOT, Ann. Soc. Linn. Lyon, 1908, p. 158 (distribution, 

 etc.). Torquilla tricolor ANT. et J. B. VILLA, Dispositio Syst. 

 Conch., etc., 1841, p. 57. P. albilabris ZIEGLER MS., according 

 to VILLA, Disp. Syst., 1841, p. 24. Pupa megacheila CAZIOT, 

 Etude Moll. terr. et fluv. Monaco, etc., 1910, p. 316, with var. 

 minor, p. 317, pi. 9, f. 19, from north of Grasse, on the short- 

 cut leading to Saint-Vallier. Pupa megacheylos DUPUY, Hist. 

 Nat. Moll. France, p. 394. 



In its typical form this species differs conspicuously from 

 avenacea by its strongly thickened white lip, the columellar 

 border more straightened, and by the development of 9 teeth, 

 the sutural fold never being found in avenacea; also by the 

 strongly compressed base and the more open umbilicus; yet 

 there are transitional forms in the Tyrol which appear to 

 connect the two stocks. These have been left as "varieties" 

 under avenacea in this work. 



