102 



NOTES AND ADDENDA. 



whorls four, the first three reguLarly spiral and not flattened for attachment, 

 except at the apex ; the last whorl diverging from the others irregularly in 

 the manner of a Vcrmetus. Length about 3 millimetres. The surface un- 

 even, with obscure wrinkles on the last whorl, and microscopic lines of 

 growth on the others. Shell thin, with delicate tubular structure, much 

 finer than that of S. carhonarius. I have not recognised this shell elsewhere 

 than in the limestoue of Eraser's Mountain, near New Glasgow, except in a 

 few rare and doubtful examples at the Joggins. It was probably attached 

 by a narrow space at the apex to submerged plants, in the manner of the 

 modern Spirorhis porrccta ; and, being broken from its attachment, or the 

 vegetable matter being removed by decay, remained loose and unattached, 

 as it appears in this limestone, some portions of which are crowded with 

 specimens. 



4. Cone-in- Cone. 



Mr H. Poole informs me that the figure of this curious concretion, at page 

 676 of Acadian Geology, should be inverted ; as, in the beds from which the 

 specimens were obtained, the conical ends of the concretions were below 

 and the flat sides above. 



5. Diabase. 



The dark-coloured dykes of igneous rock occurrmg in the Cobequids 

 have usually been regarded as diorites; but two specimens, one from a 

 dyke traversing the Upper Silurian beds at "Wentworth, another from a 

 dyke in the older Felsite series, which were kindly examined by Dr 

 Harrington, proved to contain pyroxene instead of hornblende ; and as they 

 contain hydrous silicates as well, probably products of decomposition, would 

 be included in the group now usually named Diabase. It is not improl)able 

 that other so-called diorites of the Cobequid series, in the coimty of Pictou 

 and elsewhere, may be really of the nature of diabase. Some of the more 

 coarsely crj-stalline igneous rocks occurring in this formation undoubtedly 

 contain hornblende, and are true diorites and syenites. The term Felsite 

 is used in this supplement for rocks composed chiefly of compact 

 Orthoclase Feldspar, usually with excess of Silica and sometimes 

 porphyritic. These rocks are usually termed " Compact Felspar " 

 in Acadian Geology. 



6. Neio Brunswick Geology. 



Professor Bailey informs me that rocks similar in character to the 

 Laurentian have been recognised in York County, in the interior of New 

 Brunswick. He also mentions an additional outcrop of the Acadian group, 

 flanking the Huronian rocks on their northern side, and constituting the 

 fifth parallel belt of this formation now known in Southern New Brunswick. 

 He also states that the Lower Carboniferous Albert shales are found to 

 underlie unconformably the remainder of the Lower Carboniferous forma- 

 tion, — an effect, probably, of local crumpling and partial denudation in con- 

 nexion with the changes which introduced the deposition of the coarse rocks 

 which succeed these shales. The details of these discoveries will be foimd 

 in Professor Bailey's and Mr Ells's forthcoming Reports to the Director of 

 the Geological Survey of Canada. 



