MADEIRAN GROUP. 275 



striate, and has the strise moreover (although sometimes, from 

 the worn and corroded state of the shell, difficult to examine) 

 appreciably further apart, — a peculiarity which would seem to 

 be occasioned by the alternate ones having a tendency to become 

 more or less evanescent. But beyond this prima facie feature 

 (which is about equally expressed in the examples from the 

 Madeiras and the Canaries) I can detect no character of suffi- 

 cient constancy, or importance, to warrant its separation from 

 the latter ; though the specific identity of the Madeiran and 

 Canarian individuals is, I think (as, in point of fact, might 

 naturally have been anticipated), undeniable. 



There is a smaller aspect of this shell, which was taken by 

 Mr. Lowe at the mouth of the Ribeira do Inferno, in the north 

 of the island, which appears at first sight to be so distinct that 

 it might almost represent an additional species. Nevertheless 

 since the A. striatus is eminently unstable as regards size, and 

 the examples before me (apart from their greatly reduced bulk) 

 seem merely to differ in having their surface less perceptibly 

 sculptured, I am content to cite them as the ' var. ft. depau- 

 peratus.'' 



S 



Sectio II. OPERCULATA. 



Fam.l. CYCLOPHORIDjE. 

 Genus 1. CRASPEDOPOMA, Pfeifer. 



Craspedopoma lucidum. 



Cyclostoma lucidum, Lowe, Cambr. Phil. S. Trans, iv. (»(>. 



t. 6. f. 40 (1831; 

 „ „ Pfeiff., Mon. Pneum. 51 (1852) 



„ „ Lowe, Proc. Zool. Soc. Load. 216 



(1854) 

 „ „ Alb., Mai. Mad. 72. t. 16. f. 29-31 



(1854) 

 „ „ flavescens, et neritoides, Lowe, Ann. 



Nat. Hist. vi. 114, 115 (1860) 

 Craspedopoma lucidum, Paiva, Mon. Moll. Mad. 156 



(1867) 



Habitat Maderam ; in declivibus sylvaticis intermediis 

 ubique vulgaris. In statu semifossili ad Canical abundans; 

 necnon etiam in Portu Sancto atque in ins. Deserta Australi, 

 semifossile, parcissime reperitur. 



This is the universal Cyclostomid of the Madeiran Group, 



T 2 



