April 2S, 1916] 



SCIENCE 



609 



Dr. W. A. Parks/ who recognizes among them 

 132 distinct forms. Of these 48 are ascribed 

 to known species and 31 are new to science. 

 Gastropods and cephalopods, some of which 

 are of unusually robust proportions, predomi- 

 nate. The general aspect of the Silurian 

 fauna indicates a horizon comparable with the 

 Guelph, while the Ordovician species suggest 

 the fauna of the Trenton. 



The upper portion of the Lockport member 

 of the Niagara formation in Ontario is a thin- 



arachnids were washed down a river to the 

 salt waters at its debouchure. Apparently all 

 the specimens of Eusarcus are in this instance 

 fragmentary. 



For a number of years the Devonian for- 

 mations and faunas of the western peninsula 

 of Ontario, between Lakes Huron and Erie, 

 have been under investigation by Dr. C. K. 

 Stauiler, whose final report has become avail- 

 able." The formations studied may be ar- 

 ranged in tabular form as follows: 



Devonian. 



f Portage-Chemung? Port Lambton beds. 

 Upper .-j^Qgjjggggj Huron shale. 



{Ipperwash limestone. 

 Petrolia shale. 

 Widder beds. 

 Oleutangy shale. 



Middle 



Lower 



areellus Delaware limestone. 



{Onandaga limestone. 

 Springvale sandstone (local facies). 



fOriskany Oriskany sandstone. 

 ) wanting, or possibly represented, in part, ty 

 Helderbsrg -j^ ^j^^ Detroit River series. 



bedded bituminous dolomite with intercala- 

 tions of shale. These beds ordinarily attain a 

 thickness of thirty to forty feet, and Dr. M. 

 Y. Williams, who has recently discovered in 

 them an eurypterid horizon,^ proposes for 

 them the name " Eramosa beds." The euryp- 

 terid, a new species of Eusarcus, was found 

 near Guelph, Ontario, associated with several 

 brachiopods, a bryozoan, and two species of 

 Conularia. The fauna presents a typically , 

 Lockport facies, but contains recurrent Eo- 

 chester forms as well as a single prenuncial 

 Guelph form. The association of the eur3rp- 

 terid with a purely marine fauna is sugges- 

 tive of a marine habitat for the former, but, 

 contrary to the author's statement, does not 

 necessarily prove such an environment. Such 

 an association might result if non-marine 



* ' ' Palaeozoic Fossils from a Eegion Southwest 

 of Hudson Bay," W. A. Parks, Trans. Boy. Can. 

 Inst., Toronto, Vol. XI., 1915, pp. 1-96. 



5 ' ' An Eurypterid Horizon in the Niagara For- 

 mation of Ontario, " M. Y. Williams, Geological 

 Survey, Canada, Museum Bulletin No. 20, 1915. 



The Detroit Eiver series is an eastern ex- 

 tension of the Tipper Monroe of Michigan and 

 little light is thrown upon the problem of its 

 correlation. Its fauna in Ontario indicates 

 the same curious mingling of late Silurian 

 and mid Devonian elements which character- 

 izes its occurrence in southern Michigan.^ Dr. 

 Stauffer apparently favors the reference of the 

 group to the Upper Silurian, but closes his 

 discussion with the statement that it is the 

 " ofScial practise of the Canadian Geological 

 Survey" to treat these beds as part of the 

 Devonian system. 



The Oriskany sandstone is separated from 

 subjacent and superjacent beds by uncon- 

 formities and is believed to be identical in age 

 with the formation of the same name in New 

 York state. Its fauna is distinctly a southern 

 and eastern one, and there is no evidence in 



6 "The Devonian of Southwestern Ontario," C. 

 E. StaufEer, Geological Survey, Canada, Memoir 

 34, 1915. 



7 Grabau, A. W., and iSberzer, W. H., Mich. 

 Geol. and Biol. Surv., Pub. 2, Geol. Ser. 1, 1910, 

 pp. 217-221. 



