155 
of Edinburgh, Sessio7i 1875-76. 
usage it had been subjected to had greatly injured the impressions 
on it ; they were, however, sufficiently distinct to enable me to 
give the above particulars. 
The accompanying photograph is a good one of the hind foot in 
my possession, about half the size of the original. The posterior 
pad of the foot is not quite complete, and it, together with the pads 
of the toes, are somewhat broken. 
I would propose for these foot-prints the provisional name of 
Herpetichnus loxodactylus , the oblique-toed Herpetichnus, with the 
following abbreviated character: — 
Genus Herpetichnus, Jardine (“ Ichnology of Annandale,” 
1853, p. 14). 
Herjpetichnus loxodactylus , sp. nov. 
Sp. chars. — Fore foot = 2'*3 x l'*9 ; hind foot = 3'‘5 x l /# 6 ; stride 
about 10'; impressions free ; toes 5, oblique; thumb far back; 
claws well developed. 
Locality and horizon. — Permian Sandstone, Locharbriggs Quarry, 
three miles from Dumfries. 
P.S. — In the discussion which followed this paper, Professor 
Huxley stated that so far as he could judge from the photograph 
exhibited, the markings closely resembled a foot-print he had 
described some years before in a paper read before the Geological 
Society of London, “ On tbe Stagonolepis Robertsoni (Agassiz) of 
the Elgin Sandstones ; and on the recently discovered Foot-marks 
in the Sandstone of Cummingstone ” (“Quart. Jour. Geol. Soc.,” 
1859, xv. p. 440). The resemblance of these Cummingstone foot- 
marks to the Chelichnus of the Dumfriesshire flags was noticed by 
Professor Huxley in the paper referred to. 
3. On the Decennial Period in the Mean Amplitude of the 
Diurnal Oscillation and Disturbance of the Magnetic 
Needle and of the Sun-spot Area. By J. A. Broun, F.R.S. 
(Abstract.) 
The author, in presenting results relating to the decennial period 
derived from observations made at Trevandrum during twenty-two 
years, has sought a redetermination of the mean duration of that 
