00 MADEIRAN SPECIES OF LAURIA. 



Section Lciostyla proper. 



In the Madeira Islands this section begins with species re- 

 sembling those of western Europe, of the European! 

 Tertiary and the less specialized Caucasians; but by easy 

 stages the shape becomes more cylindric, the sculpture 

 stronger, and accessory teeth develop. These tendencies cul- 

 minate in the L. f err aria group of species (Craticula of 

 Lowe), mainly inhabiting dry stations. On Porto Santo this 

 cylindric, ribbed, many-toothed line has its fullest expression. 



.26. Lauria cheilogona (Lowe). PI. 10, figs. 3, 4, 5. 



The shell is thin, perforate, rimate, with small, deep um- 

 bilical region ; ovate-conic, sides moderately convex ; apex 

 obtuse, perfect or but slightly worn. Its surface shining but 

 not glossy, very weakly, irregularly striate, chiefly near the 

 suture; of a dilute, transparent isabella color, with a trans- 

 parent brown peripheral band. Whorls are slightly convex, 

 the last slowly ascending in front, compressed laterally, the 

 base being somewhat pinched and narrowly rounded below j 

 umbilicus with a deep spiral groove. Aperture 4-plicate, 

 produced towards the outer-basal margin. Angular lamella 

 widely removed from the lip-insertion, thin, high, penetrat- 

 ing inward fulty a half whorl, irregularly serrate within. 

 Parietal lamella smaller, shorter. Columellar lamella thin, 

 broad, sloping downward. Palatal fold low, tapering slowly 

 to both ends, more than l/o of a whorl long. The peristome 

 is narrowly reflected, its inner edge thickened a little, bear- 

 ing a blunt tooth above, defining the sinulus. Length 4.1, 

 diam. 2 mm. ; 6% whorls. 



Madeira : in damp, sylvan districts, chiefly toward the 

 north, at high elevations: Lombarda das Vacas, Montado dos 

 Pecegueiros etc., on fronds of ferns (Wollaston and Lowe). 

 Near Sao Vincente (Albers). 



Helix C. cheilogona Lowe, Primitive, 1831, p. 63, pi. 6, f. 

 31. — Pupa cheilogona, Lowe, Pfr., Monogr. ii, 327 ; iv, 675. — , 

 Albers, Malac. Mader. p. 63. — Paiva, Monogr. p. 122. — 

 Wollaston, Test. Atl. p. 213. 



