116 MADEIRAN SPECIES OF LAURIA. 



strong ribbing, and especially by the very high parietal lam- 

 ella, higher than the angular. The parietal lamella is/ 

 notched where the columellar crosses it, deep in the throat, 

 and the upper-palatal is similarly notched at its upward 

 bend, for the angular lamella. 



Only two recent specimens have been found, but it is not 

 very rare in the fossiliferous beds. 



Subgenus Mastula Lowe. 



Mastvla Lowe, Ann. Mag. N. H. (2) ix, 1852, p. 278; 

 P. Z. S. 1854, p. 213 ; monotypic, for P. lamellosa. 



Short Lauriae with distinctly spirally striate embryonic 

 whorls, the rest with partially epidermal ribs, the aperture 

 short and wide with nearly simple lip. Angular and colu- 

 mellar lamella? well developed, but the parietal is small or 

 absent ; lower-palatal fold small. Basal teeth of the im- 

 mature stages are very weak or wanting. 



47. Lauria lameelosa (Lowe). PI. 14, figs. 8, 9, 10, 11. 



The shell is small, shortly cylindric or nipple-shaped, 

 shortly subturbinate, very obtuse at both ends, thin, submem- 

 branaceous, brown, not banded, lamellate-striate. Whorls 5, 

 convex, swollen, rather remotely, equidistantly, obliquely, 

 transversely ribbed with submembranaceous lamellae, which 

 spread leaf-like in the middle or are lacerated-aculeate. 

 Suture deeply impressed. Aperture semioval, depressed, 

 wider than long, 3-plicate: one ventral fold [angular lam- 

 ella] largest; one smaller columellar, situated low; a palatal 

 fold opposite this, immersed, obsolete, indistinctly visible. 

 Lip slightly expanded, very slightly sinuated, with a small, 

 obsolete denticle ; the respiratory sinus indistinct, open. 

 Length 2, diam. 1% mm.; 5 whorls (Lowe). 



Madeira : at intermediate elevations in the south ; Vasco Gil 

 ravine and Ribeira de Sta. Luzia; fossil at Canical (Wollas- 

 ton and Lowe). 



Pupa lamellosa Lowe, Ann. Mag. N. H. (2) ix, 1852, p. 

 278 ; P. Z. S. 1854, p. 214.— Wollaston, Test. Atl. p. 236. 



