June, 1889. 
OUR PHYSICAL BELIEFS. 
133 
62. Rotalia nitida. Williamson, 1858. 
Williamson (R. F.), 1858, p. 54, pi. iv., figs. 106-8. 
Robertson, D. (W. S.), 1874, rare. 
A trochoid shell, smooth, few convolutions, segments 
trapezoidal, very transparent, often of a reddish 
colour. Frequent. 
63. A onionina depressula. Walker and Jacob, 1798. 
Williamson (R. F.'), p. 97, pi. iii., figs. 70-1. 
Robertson, l). (W. S.), 1874, common. 
Oban (1883). Common. 
64. Nonionina turjula. Williamson, 1858. 
Williamson (R. F.), 1858, p. 50, pi. iv., figs. 95-7. 
Robertson, D. (W. S.), 1874, common. 
Oban (1883j. These are very fine; the final segment 
is often half the size of the shell. Common. 
65 Folijstomella crispa. Linne, 1767. 
Williamson (R. F.), 1858, p. 40, pi. iii., figs. 78-80. 
Robertson, D. (W. S.), 1874, common. 
Of this species, it will be noticed that there are few 
without the spines at the circumference, in 
connection with which read Prof. Williamson’s 
remarks. Perhaps one of the most beautiful, 
and one of the most abundant forms in many 
gatherings. Very common. 
66. Folijstomella striato-punctata. Fichtel and Moll., 1803. 
Williamson (R. F.), 1858, p. 42, pi. iii., figs. 81-2-2a. 
Robertson, D. (W. S.), 1874, common. 
Oban (1883). Common. 
67. Operculina ammonoides. Gronovius, 1781. 
Williamson (R. F.), 1858, p. 35, pi. iii., figs. 74-5. 
Common. 
PROFESSOR POYNTING ON OUR PHYSICAL 
BELIEFS. 
I have read with much pleasure the able and interesting 
paper by Professor Poynting on the *‘ Foundations of our 
Belief in the Indestructibility of Matter,” read before the 
Birmingham Natural History Society, but do not think the 
matter is yet disposed of. 
In dealing with ultimate ideas, and in fact in all reason¬ 
ing, we take for our premises an assumption that cannot be 
proved by reason of its generality, but the negation of which 
is inconceivable. Every step of the argument we base upon 
