52 



rosoma be cut open and immersed in water, the brown particles that 

 escape diffuse themselves through the fluid, and shine as numerous 

 scintillations, independent of the perfect structure. It is also wor- 

 thy of remark that general friction or contact is not essential to elicit 

 the perfect light of Pyrosoma, since touching one small portion of 

 the body is sufficient to produce a brilliant glow throughout the 

 whole. When first removed from its native element, the broader 

 extremity of this aggregate of molluscs presented a wide and circular 

 orifice, forming nearly a continuous surface with the central tube 

 constituting the interior of the body ; but when kept in a vessel of 

 sea- water, or much handled, this orifice was closed by the contraction 

 of a smooth, dense membrane at its margin, and which either obli- 

 terated the aperture, or left but a minute central orifice ; water at the 

 same time being contained in the barrel or tube of the body. Ex- 

 cept in the action of this sphincter-like membrane, no motive power 

 was perceptible in the Pyrosoma. 



" Fresh water appears to act as a powerful and permanent stimulus 

 on marine Nocfilucte. Those who have intervals of repose from their 

 phosphorescence immediately emit their light when brought in con- 

 tact with fresh water, and this fact was very strikingly exhibited in 

 the Pyrosomata. When placed in a vessel of sea-water and permitted 

 to remain quiet, these molluscs afforded no light, and when touched, 

 gleamed forth only as long as the irritating cause remained, and then 

 gradually returned to their original state. When, however, the same 

 creatures were placed in a vessel of fresh water, they never ceased 

 glowing with their brightest refulgence until life was extinct, which 

 was not until after the lapse of several hours. When also the same 

 molluscs were mutilated, or so near death as to refuse to emit light 

 upon irritation in sea- water, immersing them in fresh water produced 

 at least a temporary revival of their brightest gleam ; indeed I have 

 always felt assured that the contact of fresh water in a darkened 

 room would ever elicit the luminous power of a marine creature, 

 were the latter of aluminous nature." 



At the request of the Chairman the following notes, relating 

 chiefly to the natural history of Ireland, were read by W. Thompson. 

 Esq., V.P., Nat. Hist. Society of Belfast. 



Of the species so marked *, specimens were exhibited. 



Mammalia. 



* Vespertilio Nattereri, Kuhl. Reddish-grey Bat. I am induced 

 to exhibit a specimen of this bat, which I obtained in July 1835 

 among the ruins of Harlech Castle, North Wales, it being hitherto 

 only known as British from individuals procured in the east and 

 south-east of England. 



* Mus Hiberniais. Irish Rat. On questioning a person some years 

 ago respecting a black rat which he had seen in the north of Ireland, 

 my curiosity was excited by the statement that it had a white breast. 

 In autumn last a similar description was given me of one that had 



