[ami] outliers of the OTTAWA PALAEOZOIC BASIN 1S7 



The Utioa Formation. 



Stephandla sancta, Hinde, characterizes the Middle Utica of the 

 Ottawa Valley, and represents the Proto/.oa. 



A few G-RAPTOLiTES occur in this formation, prominent amongst 

 which are : — Leptograptus flacctdus, Hall, Orthograptus quadrimucrona- 

 tus, Hall, f'imacograptus, like C. typicah's, H., and a Dq)lograptus,\\^\m\\y 

 referred to 1). pristis, Hisinger, possibly also D. Patillus. H. 



Brachiopoda abound in the lower measures of this formation. 



Leptobohis insignis, Hall, Schizamhon fissns, var., Canadensis, Ami, 

 Lingula P rogue, Billings, Schiznrrania Jilosa. Hall, are eminently char- 

 acteristic of the Utica shales and associated limestones. Besides these, 

 Dalmanella testudinaria. Dalman, Rafinesquina afteniata, Emmons, and 

 B. delfoldea, Conrad, together with PIecfain/»uiites serirea, Sowerby, 

 Liiujnla elongata, Hall, L. Gohourgensis, Bill, L. quadrata, Eichwald, 

 are also found at this horizon in the Ordovician System. 



The L.^MELLiBRANCHiATA are represented here by Lyrodesma pul- 

 chellinn, Hall, Orthodesma paralleliim, Hall, Pterinea insiieta, Conrad, 

 Prolohella Trentonensis, Conrad, and Modiolopsis modiolan's, Hall, besides 

 other rarer and less characteristic species. 



The Pteropoda yield two species: — Coimhiria Trentonensis, Hall, 

 and C. Hiidsonia, Emmons. 



Of the Gasteropoùa the following have l)een recorded Irom the 

 Utica of this basin : — BeUeropdion hilobatas, Sowerby, rather abund- 

 ant, Clathrospira^ Hall, less frequent, Troeholifes avimonivs, Conrad, most 

 abundant, and Lophospira hli-lnrta, Hall, rarely found. 



The class Cephalopoda have afforded innumerable shells of the 

 genus Cameroceras, probably C proteiforme, Hall, Orfhoceras tenuis- 

 triatirni, Hall, Orfhoceras arnjilirameratiun, Hall, 0. lameUosum, Hall, 

 etc. 



The class Annelida is represented by SerpuJiies dissoliitns, Bill., 

 and a pretty little Conodont as yet undescribed. 



The class Trilobita has yielded the following species : — Triarthrus 

 BeckL GJ-reen, T. spinosus, Bill., T. glal)er,B., CeranrKS pleurexanthemus, 

 Green, Asaphvs latimarginatus, Hall (= A. f^anadens's. Chapman), and 

 Calymrnene senan'a, Conrad. 



Silurian. 



The Lake Temiscaming outlier of the Ottawa Palaeozoic Basin con- 

 sists for the most part of Silurian rocks. From collections made by the 

 Oeological Survey of Canada previous to 1863, and from collections made 

 by lh\ Bell in 1887 and by Mr. A. E. Barlow in the years 1893 



