CANARIAN GROUP. 319 



Hyalina osoriensis, n. sp. 



T. subro tun data, depressiuscula, subopaca, pallide albido- 

 ochracea; anfranctibus 5-6 convexiusculis, sutura impressa, 

 costulis obliquis curvatis subinsequalibus subconfluentibus sat 

 distincte sculpturatis, necnon lineolis spiralibus subtilissimis 

 subcrenulatis (subtus subevanescentibus, atque in speciminibus 

 junioribus ac bene conservatis minutissime subciliato-fimbriatis) 

 parce vel remote instructis ; umbilico magno, profundo. Diam. 

 maj. 4-41 H n . 



Habitat Canariam Grandem ; in sylvis editioribus ad Osorio, 

 Aprili 24, 1858, a Kevdo. E. T. Lowe satis copiose reperta. 



Several examples of this Hyalina were taken by Mr. Lowe 

 (on the 24th of April, 1858) in the woods on the Pico do 

 Osorio, in Grand Canary, during our visit to that remote and 

 elevated spot ; and they have so much the appearance at first 

 sight of the paler individuals of the H. lenis (from Palma and 

 Hierro) that they might well nigh be confounded with that 

 species, were it not for the minute spiral subcrenulated lines 

 with which its whorls (when viewed beneath a powerful lens) are 

 seen to be conspicuously though sparingly sculptured, and which 

 in young and unrubbed shells have a curious tendency to be 

 fringed with most diminutive filaments or hair-like scales. In 

 most other respects the H. osoriensis appears to me to be 

 nearly undistinguishable from the H. lenis, except perhaps 

 that it is even still less shining (its under-portion no less than 

 the upper, being almost free from gloss), and that its transverse 

 plicae are not quite so coarse. 



From the H. circumsessa the present species differs in its 

 rather larger size and its less flattened spire, as well as in its 

 ultimate volution being altogether more broadly developed and 

 in its umbilicus being proportionately not quite so open. Its 

 colour, too, is appreciably paler ; and its spiral lines are 

 further apart, and therefore not quite so numerous. 



The great interest, however, which attaches itself to this 

 Hyalina consists (as I have already stated) in the light which 

 it incidentally throws upon the affinities of the H. circumsessa, 

 which Mousson has regarded as entering into a section of the 

 genus Patula. I had always felt convinced that the latter 

 belonged in reality to the Hyalina group ; but now that the 

 minute ' spiral lines ' which so eminently characterise the 

 circumsessa are found to exist (however feebly) in the H. lenis 

 likewise, and to be strongly developed in a closely related form 

 from Grand Canary, both of which are unmistakeable Hyalinas, 

 and indeed but barely removed from the ordinary cellaria-tjpe, 

 there can be no longer any question that the affinities of the 

 circumsessa are with Hyalina, and not with Patula. 



