348 Linnean Society. [Dec. 5, 



tanceolatum, from Jersey, both found growing on disintegrated 

 sandstone, exhibiting a striking difference between the growth of 

 the same species on an open sunny bank and in dense shade. 



Mr. John Hogg, F.R.S., F.L.S., exhibited some scales, and a 

 piece of the scaly covering which was cut from the back of a large 

 fish found in the river Tees, in September of this year. He stated 

 that two fishermen observed a great fish — such as they had never 

 before seen — left by the tide on a sand-bank, in the estuary of the 

 river Tees. They described it as having the head of a salmon, with 

 the back-fin like that of a perch, erect, and somewhat spiny, and 

 the tail spreading and much curved. The colour they did not men- 

 tion, except that of the back, which was represented as being of a 

 purplish-black. They likewise particularly observed some large 

 scales on the front of the fish near the gill-covers, one of which Mr. 

 J. Hogg also exhibited, and which is of a very strong bony texture. 

 From the account of this fish so given, Mr. Hogg conceived that it 

 could only have been a large Tunny {Thynnus vulgaris of Cuvier), 

 which had been stranded whilst in pursuit of herrings or other small 

 fishes. MM. Cuvier and Valenciennes in their ' Hist. Nat. des 

 Poissons,' tom. viii. p. 57, separated the Tunnies from the Mackerels 

 (Scomber), in consequence of the "remarkable disposition of the 

 scales on the thorax, which are larger and more unpolished than 

 the others, and form around that part a sort of corselet?" They 

 also describe the corselet of the Common Tunny thus : — " Le corselet, 

 c'est-a-dire cette portion du tronc couverte d'ecailles plus grandes 

 et moins absorbees dans la peau, est considerable." (p. 62.) This, 

 however, would seem to lead to an incorrect view of the smaller 

 scales on the back, which are, as it were, enclosed between two 

 skins, and are placed in a somewhat imbricated manner, resembling 

 the arrangement of the slates upon a roof, and cannot properly be 

 termed " absorbees dans la peau." Mr. Hogg showed the nature of 

 the piece of the external covering which the fishermen had cut off 

 the back ; the outside skin being of a dark, or nearly black colour, 

 and of a coriaceous substance. The white scales, imbedded in it, 

 are similar to those forming the corselet near the gill-covers, but 

 they are much smaller, and so closely placed by one overlapping the 

 other, that they constitute a perfect defence against nearly every 

 kind of danger. The piece so cut off the back f the fish, which 

 was done with some difficulty, resembling a portion of a shield, 

 would seem to be (from the close disposition of the osseous plates 

 or scales enclosed between two skins) proof against large shot, or 



