NOTES AND QUERIES. 293 



to rather more than 15 grains (apothecaries' weight), 480 grains to the 

 ounce, and as a gallon of water weighs 10 lbs. or 70,000 grains, we get 

 1500 grs. : 70,000 grs. : : 4 drops : 186f drops; or, roughly speaking, we 

 may add for every gallon of water in the aquarium 186 drops (or one 

 dessert-spoonful) of the solution recommended. This recipe, it is said, will 

 keep the water fresh for three months without renewal. 



MAMMALIA. 



The Cost of Rabbit Destruction in Australia. — The Hon. J. Salamon 

 I'ecently stated, in the Legislative Council of Sydney, that up to that time 

 7,853,787 Rabbits had been destroyed and paid for at a cost of £301,49^. 

 This represents the very large sum of Hid. per rabbit, and, adding to this 

 a proper proportion of the bonuses paid by stock-breeders, farmers, and 

 others, each Rabbit killed is found to have cost about Is. 3d. In other 

 words, it costs as much, or more, to kill a Rabbit in AustraUa as to buy 

 one in England. 



On the Bats found in Merionethshire. — The following notes on the 

 Bats inhabiting this part of Merionethshire may prove useful to those who 

 ai'e interested in the distribution of the British species. Up to the present 

 time I have obtained specimens of six species, five of which occur more or 

 less commonly, though none of them are very abundant. The sixth, the 

 Lesser Horse-shoe Bat, is very sparsely distributed, although it can scarcely 

 be called rare. 



(1). Vespenigo noctula. — The Noctule is a common species, although it 

 seems not to have been previously recorded from any part of Wales. It 

 frequents most of the wooded parts of the district, especially such as have 

 the hill-sides covered with oak trees. I have observed it plentifully in fine 

 weather flying over the extensive marshes near Port Madoc. 



(2). Vespenigo plpistrellus. — This bat is not nearly so abundant as in 

 most parts of England, and, except in the immediate vicinity of houses, is 

 probably outnumbered by several other species. Although the smallest of 

 the British bats, the Pipistrelle frequently preys on rather large insects ; 

 the crane-fly, Tipula oleracea, commonly known as " daddy-longlegs," 

 apparently forms a considerable portion of its food. 



(3). Vespertilio daubentonii. — This is a common species in those 

 localities where it occurs ; but, from the nature of its haunts, it might 

 easily be passed over unless sptscially looked for. It frequents pools of 

 stagnant water, or slow-runuiug rivers, giving a decided preference to the 

 latter. On any still warm night it may be seen flying slowly and steadily 

 as close us possible to the surface of the water, into which it frequently dips 

 its nose, probably for the purpose of taking some floating insect. The cry 

 of Daubenton's Bat is very weak and shrill, sometimes prolonged into a 

 6ort of chatter. 



