42 Mr. R. T. Lowe on a new Madeiran Helix. 



doubtedly a good genus, though it is a mistake to cite the 

 Lucernaria cyathiformds of Sars as representing it. 

 I remain, Gentlemen, 



Very faithfully yours, 

 Edinburgh, June 1860. Geo. J. Allman. 



X. — Description of a new Helix ; and Notice of the Occurrence 

 of Planorbis glaber, Jeffr., in Madeira. By R. T. Lowe, 

 M.A. 



[With a Plate.] 



During an excursion in the north of Madeira, a few weeks past, 

 I had the good fortune to discover the following fine and entirely 

 new Helix, living at an elevation of about 4000 feet, on a dry and 

 partially wooded mountain-slope or bank, along the new Levada 

 now constructing in the Ribeiro do Fayal. Its affinity is pri- 

 marily, doubtless, with the rare Desertan fossil, H. coronula, 

 Lowe ; and next, though more remotely, with H. tiarella, Webb, 

 and with the recent Porto-Santan H. coronata, Desh. Yet it 

 exhibits also, both in size and certain peculiarities of form and 

 sculpture, the nearest approach yet discovered amongst living 

 Madeiran Helices to the strange and curious H. Delphinula, 

 Lowe, known at present only as one of the most abundant 

 Canical fossils of Madeira. 



The discovery of so fine a recent species ought to stimulate 

 afresh the researches of naturalists in the higher sylvan regions 

 of the island, considering how remarkable it is that so large and 

 striking a shell as this, however rare and local it may be, should 

 have hitherto escaped all observation. 



The main points of interest attaching to H. delphinuloides, 

 independently of its great rarity and beauty, are — 1st, its sup- 

 plying in some sort a link between the two remarkable Madeiran 

 groups Craspedaria and Coronaria, in size agreeing better with the 

 single known representative of the former, H. Delphinula, than 

 with any previously described member of Coronaria; and 2ndly, 

 its offering a living analogue, in the group Coronaria, to the 

 fossil type, and indeed sole representative, of Craspedaria. The 

 abundance, moreover, of H. Delphinula in a fossil state, and its 

 apparent extinction as a living species, are curious facts when 

 contrasted with the extreme rarity of its recent representative, 

 H. delphinuloides, and the absolute non-occurrence of the latter 

 as a fossil. But since the possibility of the one being a mere 

 modification of the other is entirely inadmissible, the discovery 

 of H. delphinuloides doubtless strengthens much the probability 

 of the existence also in a living state of the true H. Delphinula 

 itself in some of the many still unexplored sylvan nooks and 



