32 LOWER PENINSULA. 



Diaphragms regular, complete, but often compound, angular on 

 the surface through intersection with the lateral squamae. 



On the lateral surface of the subcylindrical polyparia, many- 

 orifices are found closed by concave opercula of concentrically 

 wrinkled structure. Some of them have a small opening in the 

 centre, which is finally closed up when the operculum is finished. 



Found frequently in the drift of Michigan in silicified condi- 

 tion, partly in hemispherical masses, with a flat under side cov- 

 ered by an epitheca, or in elongated, cylindrical or tuberose form. 

 Similar specimens occur in the corniferous limestone of Canada, 

 New York, and at the Falls of the Ohio. At the latter locality, 

 large convex masses are found, which are often erroneously iden- 

 tified with Favosites maximus, Troost. They are absolutely iden- 

 tical in structure with the described smaller forms. 



Plate IX. — Fig. i is a representation of two small silicified 

 specimens from the corniferous limestone of Port Colborne. The 

 upper specimen seems to me identical with the American speci- 

 men of Favosites basaltica figured by Goldfuss. Its base and the 

 lower specimen exhibit orifices closed by concave opercula. Fig. 

 2 is a silicified specimen from the Falls of the Ohio, presenting 

 open tube channels intersected by diaphragms, and with the walls 

 perforated by very numerous pores. It shows at the same time 

 the divergence of the tubes from a basal centre. The rows of 

 lateral squamae are not as conspicuous in that specimen as in many 

 others. 



FAVOSITES WINCH ELLI, Rominger. 



Vide " Silliman's Journal," November, 1862. 



Massive convex polyparia, composed of rounded-polygonal tubes 

 from three to four millimeters in diameter. Diaphragms com- 

 plete, simple, warped and depressed at the margins into several 

 siphon-like pits, or the whole diaphragm is depressed into one deep 

 excentrical funnel. Tube walls striate by twelve well-marked lon- 

 gitudinal furrows, destitute of lateral squamae. Pores small, sur- 

 rounded by a projecting rim, in one or two rows on each side, and 

 somewhat remote in position. 



Found frequently in the drift deposits of Michigan. Some 

 specimens are inclosed in a white sand rock, associated with Oris- 



