CANABIAN GROUP. J569 



This may perhaps be regarded as the representative in Grand 

 Canary of the TenerifFan H. malleata, Fer., though in reality it 

 comes far nearer in its opake granulated surface and the obsolete 

 teeth of its peristome, as also in its less sylvan mode of life, to 

 the H. nivarice. It is widely spread over the intermediate dis- 

 tricts of Grand Canary, descending in a subfossil condition to 

 quite a low altitude, for I have met with it, genuinely subfossil- 

 lized, on the calcareous isthmus between Las Palmas and the 

 Isleta. In a recent state it was taken abundantly by Mr. Lowe 

 and myself throughout the region of El JNIonte, as well as within 

 the Great Caldeira of the Bandama mountain, and on the calca- 

 reous ground between Lagaete and Gaidar ; and it is recorded 

 by Mousson as having been obtained by Fritsch likewise in 

 Grand Canary. It was first detected by Webb, in a bleaclied 

 and decorticated condition, during August of 1829, who however 

 mistook it for the H. malleata. 



Apart from its smaller size and opake, coarsely granulate 

 unmalleated surface (the granules of which are formed as it were 

 by the broken-up closely-packed transverse lines of growth, and 

 extend over the very nucleus itself, — the basal portion, which is 

 bright and glossy, being alone devoid of them), the i7. Glasiana 

 recedes from the malleata in being (as regards its ground-co- 

 lour) of an altogether much paler or yellower hue, there being 

 no indication of the deep rich olivaceous- and coffee-brown tints 

 which are so characteristic of that species ; its ultimate volution, 

 which descends much less in front, is free from all traces of a 

 keel even behind ; and its aperture is not only more rounded 

 and very differently shaped, but it has the tooth-like callosities 

 obsolete, — the one towards the middle of the outer lip being 

 represented by a mere thickeningof the peristome {usually slight 

 but sometimes considerable, and for the most part more strongly 

 expressed in the subfossilized examples), while the other, which 

 is so enlarged and conspicuous at the upper angle in the H. 

 malleata, is uniformly and completely wanting. Its peristome 

 is often, though by no means always, of a pinkish or flesh-coloured 

 tinge ; with the basal margin straightened, or even subconvex, 

 internally, instead of being (as in the H. m^alleata) concave. 

 The H. Glasiana measures about 10 lines across its broadest 

 part, and has an altitude of about 7^ or 8. 



Mousson's subfossil ' var. defonnis ' which he affiliates with 

 the Teneriffan H. malleata, but which he records to have been 

 found by Grasset at ' Puerto da Cruz ' in Grand Canary, requires 

 further explanation, for I cannot but think that it will be ascer- 

 tained in reality to be referable to the H. Glasiana, — the sub- 

 fossilized examples of which have their peristome greatly 

 tliickened (causing the aperture to appear smaller and more 



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