112 PHILOSOPHICAL TRANSACTIONS. [aNNO l6g6. 



wliere the animal lies is marvellous : tiiere are two decks visible, one above 

 another, of a pearl colour; there is a hole in the upper deck naturally, through 

 which may be seen the other deck at some distance from the upper, and such 

 another hole in it ; the higher part of the shell, which resembles a helmet, 

 where it is broken, shows several vaulted divisions^ between which passes a tube 

 that is hollow : they are of the colour of pearl too. The outermost coat of the 

 shell is of a dark grey colour, which is much worn off in this specimen, and 

 there appears a smooth coat, with brown and white streaks. 



The next is that which Boccone calls the pediculus ceti. It is of one valve ; 

 but what is singular, it is open at both ends ; the structure of it is throughout 

 very curious ; the animal was so dried, that I could not distingush its parts ; 

 but it must be of an odd shape, if it fit the sinuous caverns in the inner part 

 of the shell. 



The testudo marina squamosa* is sometimes cast on the Orkney isles ; the 

 shell of one sent to me, was 2 feet in length, and of a proportionable breadth. 

 There is a great variety of the patellae or limpets found in the isle of Sky. Be- 

 sides the common patella, there is one of a middle size, of a dark grey colour, 

 which is much flatter than the common patella ; the circle about the peak is of 

 a lighter colour; many striae run from the peak to the border, and it has 

 another larger circle near the border. There is another flat one, also of a grey 

 colour. 



There is a conical limpet, raised, with the peak white, and a circle below it 

 of an orange colour ; the rest below that of the same colour, variegated with 

 black spots. There is a conical one too of a middle size, smooth and brownish, 

 with a white peak. There is an oval limpet,-^ of a fucal size, thin and trans- 

 parent, the peak of a dark colour ; in the convex part below the middle, there 

 are some blue and very beautiful lines. 



There is a great variety of the trochi likewise. The trochus albidus maculis 

 rubentibus distinctus, a large and a lesser sort of them. A trochus of a middle 

 size, of the colour of pearl all over ; which was taken up out of the sands. A 

 trochus of a reddish colour, marked with dark spots. A trochus of a colour 

 between blue and grey, marked with dark spots ; this had a cancellus in it. I 

 have been told too, that there is in the isle of Sky a trochus of a gold 

 colour. 



Cochlea Umbilicala. — There is a small sort of the cochlea umbilicata, with 

 waves of a brown colour on a white ground. There is a lesser cochlea umbili- 

 cala, with darker waves on a white ground. 



* Testudo imbricata. Lin. f Patella pellucida. Lin. 



