Linncean Society. 299 



remarks on the Long-eared Bat (Plecotus auritus) as observed in 

 Ireland. 



The occurrence of the Larus Sabini in Ireland on two occasions 

 was next adverted to. Of this bird two specimens only had pre- 

 viously been recorded as met with in the eastern hemisphere, both 

 of which were obtained by Captain Sabine at Spitzbergen. The 

 specimens which formed the subject of the present paper were 

 rendered peculiarly interesting from being in the plumage of the 

 first year, in which state the Larus Sabini had not before come 

 under the inspection of the naturalist. The appearance presented 

 by the species at this age was described with great minuteness, and 

 also the differential characters by which it may at all ages be di- 

 stinguished from its congener the Larus minutus. 



The specimens described are contained in the Museums of the 

 Natural History Society of Belfast and the Royal Society of Dublin. 



From the examination of a specimen of the Cygnus Betvickii, 

 killed in the North of Ireland, and preserved in the Belfast Museum, 

 the author stated that he was led to discover that some of the cha- 

 racters by which this species has hitherto been distinguished are 

 erroneous. 



The principal character pointed out as such was the number of 

 rectrices, or tail-feathers, which are described in the Linn. Trans, 

 (vol. xvi.p. 445, et ££9.), Ill us. of Orn. (Part 6), Illus. of Brit. Orn., &c, 

 to be 18, though they are in reality 20. The correctness of the 

 view respecting this and the other characters thus dwelt upon was 

 subsequently confirmed from an inspection of two living birds, which 

 have been since Feb. 1830 in the possession of William Sinclaire, 

 Esq., of the Falls, near Belfast. 



Observations on the disposition, habits, &c, of these individuals 

 were also added. 



Mr. Thompson embraced this opportunity of exhibiting a specimen 

 of the Potamogelon prcelongus of lleichenbach, with which he had 

 been favoured by William Henry Harvey, Esq., of Limerick, who 

 had the satisfaction of discovering the plant last autumn in the river 

 Shannon, and thereby making a very desirable addition to the 

 British Flora. 



May 6. — The reading of Mr. Thompson's paper was resumed and 

 concluded. 



The Three-spined Stickleback of the North of Ireland was dwelt 

 upon at considerable length, and the differential characters between it 

 and the three English species, as described by Mr. Yarrell (Mag. of 

 Nat. Hist., vol. iii.) pointed out. From all of these it was stated to be 

 distinct, but seemingly identical with the Gasterosteus brachycentrus 

 of the Histoire Naturelle des Poissons of C uvier and Valenciennes, (torn, 

 iv. p. 499. pi. 98.) a species there published as new, and mentioned 

 as having been obtained by M. Savigny from the brooks of Tuscany. 



The discrepancy between C uvier (Regne Animal, 2nd edit.) and 

 British authors relative to the Gasterosteus pungitius of Linnaeus 

 was next noticed. 



It was remarked of the Gobius niger from specimens taken in the 



20.2 



