314 Scientific Notices — Mineralogy. [Oct. 



orthoceratite from Lake Huron, seven inches long, nearly two 

 inches broad at one end, and one inch and a quarter at the 

 other. One face of the fossil presents the usual cellular divi- 

 sions ; but the reverse exhibits the appearances exhibited in 

 fio\ 12 (PI. XXXII). At the larger end of this specimen, the 

 siphuncle is of great magnitude ; but at the smaller, it is not 

 much more than a quarter of an inch in diameter. Its chambers 

 are very unequal." 



" The isles on the north of Lake Huron possess a curious and 

 complicated chambered shell which approaches nearest to an 

 orthoceratite. There are at least three varieties." 



Conularia. — Three specimens of C. quadrisulcata were found 

 at the falls of Montmorenci. 



Euomphalus, Trochus, and Turbo, are the only unchambered 

 univalves that Dr. Bigsby found in Lake Huron. 



Terebratula, abound everywhere. The most common species 

 are T. bicarinata of Lesueur, and T. subrotunda. 



Products. — Abundant in almost every locality. They are 

 often of chert. 



Encrinis. — E. prominens, E. verrucosa, and E.feevis, together 

 with pentacrinital columns are plentiful every where, but rarely 

 with ramifications or stomach. 



CaryophylUa have been found in great numbers in the south 

 of Lake Erie. 



Turbinolia. — This species of madrepore abounds in the Lake 

 of the Woods, and the great lakes, but is much more rare at 

 Montreal and Quebec. 



Astrea. — A. basaltiformis in the limestone of the river Detroit? 



Cellular and chain madrepores, tubipa strues, and ramosa, 

 retepores, and flustra, are in great abundance everywhere. 



Nine varieties of a new genus of madrepore, having the form 

 of a vertebral column, sometimes two feet long, were discovered 

 at the Manitoulines of Lake Huron, by Mr. White, the medical 

 officer of the British military station on Drummond's Island. 

 They have been described in the Geological Transactions. 



" The following shells are known only in the more recent 

 formations. The delicate bivalve, the lingula (crag, London 

 clay), occurs in considerable numbers among the trilobites and 

 orthoceratites of Lake Simcoe, and in well-marked specimens. 

 They are oval, or suboval, and rather longer than half an inch. 

 They are casts which frequently retain the original shell of a 

 glossy hair-brown colour. 



" Mr. Say, of Philadelphia (to whom I am under many obli- 

 gations), pronounced with great hesitation, on account of acci- 

 dental defects, or the concealment of the hinge, upon what he 

 supposed to be the clypeaceous univalve, calyptrsea (crag above 

 London clay), from Lake Simcoe, an unio (cornbrash, &c), a 

 mytilus (coral rag, &c), both from the north-east coast of Lake 



