Correspondence. 357 
of the Rocky Mountains. To the first objection,! answer that I considered 
it premature to enter into any speculations about the relative position of a 
lot of fossils of apparently new form accidentally picked up by a transient 
traveller, who had no time for examination of tlie stratigraphic position of 
the beds. I thought so, the more as I determined as soon as I saw the 
fossils, to go and see the locality myself; I have done this since, and suc- 
ceeded in gathering an abundance of the already described bpecimens, but 
I did not find, as I had expected, any notable amount of additional new 
forms of sufiicient importance to call for a special publication. Also the 
stratigraphy of the huge mountain mass I found so complicated, that the 
short time I could devote to the investigation of the locality appeared to 
me insufficient to ascertain the stratigraphic order of the exposures. I 
desisted therefore from such attempt, as it would have required 
weeks or even months of dangerous work on almost inaccessible mountain 
slopes scarcely possible for a single person without any assistance, and not 
provided with camping equipments. 
These are my reasons why I did not make a further communication 
about Mount Stephen, its geological structure, and its fossils. Incidentally 
I may here make the statement that the base of the mountain is pretty 
well exposed by cuts of the Canadian Pacific Railroad. It consists of a very 
large succession of granular Quartzite beds,some of them perforated with 
frequent vertical tortuous channels known as Scolithus, but no other recog- 
nizable organic remains. Inter-stratified with the quartzite beds are belts of 
bluish or greenish dark slate rock more or less fine grained and silky, 
shining or in other cases dull, earthy,gritty,or calcareous. In one of these 
slate seams cut by the road bed, I found sparingly fragments of Conoceph- 
alus cordillerai or as Mr. vValcott prefers, of Ptychoparia, likewise are 
minute Linguloid shells or Obollelas here and there scattered, and in one 
slab I noticed a fragment of the head of Ogygia klotzii. lu the upper 
horizon of theQuartzitic series, beds of a dark blue siliceous limestone are 
intercalated, and higher still a belt of dark blue limestone many hundred 
feet in thickness shows itS' face iu the unaccessible rockwalls. No fossil 
could be discovered in the limestone blocks tumbled down trom above. 
The strata,inclosing a prolific number of well preserved specimens of 
Trilobites, but a very restricted number of species, are evidently superin- 
cumbent on these limestones and present themselves in precipitous,scarcely 
accessible slopes of slate rock 3,000 feet vertically above the railroad track. 
The succession of beds in this slate belt amounts to not less than a thousand 
feet, the fossils oc^ur principally in the uppermost layers. In the lower 
ones I found none. Above the slate beds carrying the Trilobites a repeated 
alternation of quartzite beds and of belts of limestone with a series of 
sericitic slates forms unaccessible rockwalls, up to the top of the snow 
covered mountain. These upper sericitic slates are on the line of the 
road west of Mt. Stephen largely exposed and seem to compose entire 
mountains from bottom to the top; they are as far as I could ascertain to- 
tally devoid of fossils. 
The second objection of Mr. Walcott, that I neglected to compare the 
fossils with similar forms described from theCambrian strata of the Rocky 
