326 NATURAL HISTORY MISCELLANY. 
the Pacific Ocean by Prof. J. D. Dana, while in the United States Ex- 
ploring Expedition. Others have been described and figured by Major 
a? in the TREE Journal for 1866 :— 
+h 
with them. When swallowed by, or entangled 
‘with other creatures; they in their turn appear to be also luminous. They also give 
them. When they are at rest, they gradually 
cease to five out light; but as soon as they are disturbed or in com ¿or the vessel con- 
taining them is shaken, they again become bright, even after many hours’ confinement. 
beard pre seen the ship’s deck running with liquid fire when the net containing this 
species had been rien on board. 
+ 
CORRESPONDENCE. 
L. Q., Pennsylvania, asks for information regarding the prepara- 
tion of snail’s tongues for microscopical objects. They are generally » 
mounted in Canada balsam, using a thin piece of glass as a cover to 
the preparation. 
To dissect the membrane from the mouth, one must use needles for 
the very small snails, and fine knives for the la arger species. One can 
cut with certainty on such snails as Helix albolabris, iss slitting the 
cesophagus open from above, care being taken not to cut the jaw, 
teeth is quite tough, and can be picked away with needles. For the 
minute snails the readiest way is to pick the head in small pieces on 4 
glass slide. With the microscope, the portion containing the tongue 
ith considerable care and patience the tongue may be removed 
entire. During this work the preparation must be well moistened; & 
drop of water is sufficient. — 
E. L., Illinois. — The following works have been published on North 
, American Lichens : SR ‘aa of the Lichens of New England, the 
other North American States, and British America.” By Edward Tuck- 
erman, A. M., Cambridge, 1848. 1 vol. 8vo, 93 pp. ‘‘An Enumeration 
of North American Lichens, with a a Preliminary View of the Struc- 
ony and General History of these Plants, and of the Friesian System,” 
' By Edward Tuckerman, A.M. Cambridge, 1845. 8vo, pp- 59- 
Ww. H. S., Minnesota. — You will find Shirley Hibbard’s Book of the 
Aquarium, published in London, 1856, the cheapest and best manual 
