360 0. CALLAWAY ON THE NEWEE GNEISSIC 



branches. Round or oval markings, like those on the Stigmaria of 

 the coal, are also not uncommon." This description appears to me 

 strictly correct; and, in addition, I have observed in well-preserved 

 specimens that the stems, which are hollow in the centre, present 

 the appearance of several distinct concentric coats. Whatever this 

 structure may mean, it appears clear that the fossils were true 

 plants, and that they were of by no means the lowest type. I can 

 hardly think but that woody tissue was present in these stems. 



Salterella (Serpulites) Maccullochii .will complete, so far as I 

 know, the list of fossils. Salter describes these minute forms as 

 " short, subcorneal, and curved tubes, of thick substance, and with 

 but a slender central perforation ; " and he compares them to 

 Ditrupa. I have, however, obtained specimens in which a distinct 

 cone-in-cone structure is visible, as in Piloceras of the Durness lime- 

 stone. Transverse sections show the edges of three concentric 

 septa (?), as in Salter's plate* (fig. 21), and as in the conical fossils 

 described above. These puzzling little things appear to be more like 

 Cephalopods with conical septa than Annelids or Pteropods ; but 

 their small size, under 1 inch, suggests a doubt., 



As we know of no undisputed fossil remains in undoubted 

 Archaean rocks, the facts just enumerated seem to bear against the 

 Archaean age of the Assynt series. On the whole, I see no sufficient 

 reason to deny the received view of the correlation of this group ; 

 but, since a doubt remains, I have preferred to use a local desig- 

 nation. 



2. Subdivisions. — As I shall have to submit evidence to prove the 

 frequent inversion of the Assynt series, it is of the first importance 

 that we should ascertain the order of its subdivisions in their true 

 position. I must here assume, what I shall hereafter attempt to 

 prove, the non-existence of the so-called " Upper Quartzite " and 

 " Upper Limestone " of Xlurchison. The chief horizons which I 

 have recognized are the following : — 



c r Torriclon Sandstone and Ben More Grit. — The ordinary Tor- 

 ridon is too well known to need further description ; but the variety 

 which I have called " Ben More Grit" requires special notice. A 

 little below the top of Coniveall (3234 feet), the western peak of 

 Ben More, is a band of grit and conglomerate, hitherto grouped with 

 the " Upper Quartzite," of which it forms the base. The lowest 

 beds of this series, as seen in a precipice 600 or 700 feet below the 

 summit in the spur which projects to the south, are greenish con- 

 glomerates. The included fragments, which are well rounded, are 

 mainly of quartz and gneiss, the former sometimes reaching a diame- 

 ter of 6 or 7 inches, and are imbedded in a chloritic matrix. These 

 basement conglomerates pass up into a green grit (No. 94, p. 417), 

 alternating with finer green sediments. Mr. G. H. Bailey, B.Sc, 

 who accompanied me in 1881, descended from the peak by a route 

 which afforded him a clearer section of the higher beds than the line 

 followed by myself in 1882 ; and he states that he " came upon Tor- 

 ridon, somewhat changed in aspect, after about 300 feet of descent. 

 * Quart. Journ. Geol. Soc. 1858, pi. xiii. 



