INDEX. 
Alcock Thomas, M.D. — On the Structure of the Shells of several com- 
mon species of Polymorphina, p. 67. 
Bailey Charles, F.L.S. — On the Occurrence of Potamogeton . Zizii, M. 
and K., in Lancashire, and in Westmorland, p. 40, On the 
Lancashire locality for Selinum Carvifolia, L., p. 44. 
Bottomley James, B.A., D.Sc., F.C.S. — On the Formula for the Intensity 
of Light transmitted through an Absorbing Medium, as deduced 
from Experiments, p. 4. On the Intensity of Light that has been 
transmitted through an Absorbing Medium in which the Density 
of the Colouring Matter is a function of the distance traversed, 
p. 7. 
Boyd John. — On the Male of Argulus Foliaceous, a parasite found on 
the Carp, p. 99. 
Brockbank Wm., F.Gr.S. — On the Levenshulme Limestones — a Section 
from Slade Lane eastwards, p. 61. 
Darbishire G-. — Note upon the Mammoth Cave, p, 55. 
Darbishire B. D., F.G.S. — On the animals taken in a dredging at Oban, 
p, 45. . 
Gwyther B. F., M.A. — On a Compound Bainbow, p. 3. A Proof of the 
Addition Theorem in Elliptic Integrals, p. 81. 
Joule J. P., D.C.L., LL.D., F.B.S. — Note on the Dimensions of Ships, p. 
19. On a fresh determination of the freezing point in a sensitive 
thermometer, p. 47. On the use of Lime as a purifier of the 
products of combustion of coal gas, p. 55. On an Arrangement 
for damping the small oscillations of a telescope, p. 104. 
