194 TEST ACE A ATLANTIC A. 



Helix coronata, Pfei/., Mon. Hel. iii. 146 (1853) 



Lowe, Proc. Zool. Soc. Loud. 194 (1854) 



Alb., Mai. Mad. 35. t. 8. f. 31-34 (1854) 



Paiva, Mon. Moll. Mad. 65 (1867) 



Habitat Portum Sanctum, et (sec. Paiva) ins. parvam adja- 

 centem 'Ilheo de Cima;' recens a meipso in cacumine extreme 

 orientali 'Pico de Baixo' dicto, A.D. 1848, detecta. Semifossilis 

 ubique (in Portu Sancto) copiosissime reperitur. 



Although not differing much from them in breadth, the 

 H. coronata (which measures scarcely 3 lines across its widest 

 part) is the smallest of the six members of the section Coro- 

 naria which have hitherto been detected ; and although it is 

 a most abundant species in nearly every subfossiliferous deposit 

 of Porto Santo (to which island, and the Ilheo de Cima, it is 

 peculiar), it was not until 1848 that it was ascertained to 

 belong to the present fauna, it having been found by myself, 

 during that year, in a living state, on the north-east side of the 

 extreme summit of the eastern- peak (opposite to the Ilheo de 

 Cima) known as the Pico de Baixo. I obtained it, in that 

 particular spot, in profusion, beneath slabs of stone and at a 

 considerable depth underground, the specimens adhering to- 

 gether in clusters ; and the Baron Paiva states that examples 

 were sent to him in 1863, as having come from the Ilheo de 

 Cima, which, topographically considered, is a sufficiently pro- 

 bable habitat. 1 



The H. coronata is a rounded, flattened, sublenticular little 

 shell, solid in substance, but nevertheless (when in a living 

 state) rather shining (which is peculiar for the present section) 

 aid subhyaline', it is also strongly though sparingly sculptured 

 (or embossed), and either of a very pale whitish horny-brown or 

 else of an undiluted clear white. Its umbilicus is rather large 

 and spiral ; its aperture (which is constricted behind, and very 

 suddenly deflexed) is small, sinuate, distorted, and subtrian- 

 gular, the base of the triangle, or outer lip, being armed 

 internally with a thick, powerful, obtuse tooth ; and its peri- 

 stome is acute and continuous, and a good deal developed. 



1 Although I have admitted the Ilheo de Cima, on the authority of the 

 Baron Paiva, as a locality for this species, I really cannot, without further 

 and better evidence, cite its occurrence, as he has done, in the subfossiliferous 

 deposits of Madeira proper, for no other naturalist has reported it beyond 

 the limits of Porto Santo, and the extreme inaccuracy as regards habitat of 

 the Baron's material, which was almost invariably brought to him by paid 

 collectors sent out from Funchal, and which was sometimes (as I have proved 

 to a demonstration) indiscriminately mixed up afterwards even by himself, 

 renders it more than likely that some of his Porto- Santan examples had be- 

 come accidentally transposed (as was so often the case in other instances) 

 into his Madeiran boxes. At any rate I feel that it is better to omit it from 

 the Madeiran list than run the risk of perpetuating what might possibly be, 

 and probably is, a serious topographical blunder. 



