Mr. Tate on Acmcea testudinalis. 213 



of a flattened oval shape, l^'vn. long, by f broad, of a dirty 

 white colour, and close uniform texture. It had completely 

 invested a small Buccinum undatum, in which the crab was 

 a sojourner, and thrown an ample whorl around it, which 

 was furnished with a well formed mouth and regular lip, 

 strikingly imitative of the fabrications of a true shell-bearing 

 mollusc. Montagu first remarked the parasitism of this sponge 

 on shells enclosing the Pagurus. In the Edinburgh New 

 Phil. Journal, VIII., (1830,) p. 235, 236, Dr. Coldstream 

 gives an account of this sponge which had attached itself to a 

 Turritella terebra inhabited by a Pagurus, and so enlarged it 

 by two additional turns, that it became like a Buccinum. 

 His explanation is similar to mine. " The Crab takes pos- 

 session of the Turritella when young; the sponge then attaches 

 itself to the shell, and, as it grows, is forced, by the motions 

 of the crab, to assume a spiral form, with a cavity enlarging 

 towards the mouth, corresponding to the progressive develop- 

 ment of its crustaceous inhabitant." In the British Museum 

 List of British Sponges, the specific name of this Halichondria, 

 is altered to domuncula=Alcjom.\im. domuncula of Olivi. I 

 sent my specimen to the British Museum. 



Nanophyes Lythri. This pretty Curculio I found on 

 Lythrum Salicaria, at Spindlestone Pond, in 1848; and again 

 in 1860 at Hetton Burn, in company with Mr. Boyd. It is 

 common in the latter locality. 



Vanessa Id ; Peacock Butterfly. One on the border of 

 Penmanshiel Wood, in May. 



Notes on the distribution of AcmcBa testudinalis. 

 By George Tate, F.G.S. 



The recent discovery of new localities in our district for the 

 pretty, smooth, tortoise-shell Limpet — the Acmsea testudinalis 

 — suggests inquiry into the history of its distribution. 



It is a boreal species inhabiting the shores and seas of 

 Greenland, Norway, Zetland, the Orkneys, and the northern 

 parts of North America. It has, however, been long known 

 to range along the western coast of Scotland and to be pretty 

 abundant at the Isle of Arran and among the Hebrides. Not 

 many years ago it was first seen on the Irish coast ; but it is 

 now known to extend as far southward as Dublin Bay. It 

 was observed on the north coast of the Isle of Man in 1836, 

 where it has since considerably increased ; but it has not yet 

 been discovered on the west coast of England or Wales. 



Oo 



