62 LOWER PENINSULA. 



of thin-walled tubes with nearly contiguous orifices. The granu- 

 losa decorations of the interstitial surface are obscure in this spec- 

 imen. 



DENDROPORA NEGLECTA, N. Sp. 



(Compare Farwsiies polymorp/ia, Billings, Canad. Journ., 1859, p. in, Fig. 

 12, with exclusion of the other figures.) 



Stems from five millimeters to two centimeters in diameter, with 

 irregularly straddling branches. Orifices very unequal, circular or 

 oval, narrow, funnel-shaped, oblique, or almost rectangular to the 

 surface, surrounded by a prominent rim, or nearly even with the 

 interstitial surface, which is quite spacious and decorated with 

 ridges and granulations as in the former species. Many of the 

 stems, however, are nearly smooth on the surface, either through 

 the wearing off of the decorations or through original want of 

 their development. Older stems are sometimes found with nearly 

 solid surface, the orifices having become narrowed to minute 

 punctiform openings by excessive incrassation of the tube walls. 

 The central portions of the stems are always formed by thinner- 

 walled tubes or tube ends, with subangular outlines and of regu- 

 lar Favosites structure, having connecting pores, transverse dia- 

 phragms, and being longitudinally striate by faint spinulose ridges. 



Found in the drift of Michigan, associated with other fossils of the 

 corniferous limestone formation. It is found in place at Port Col- 

 borne, Canada, at Caledonia, N. Y., and at the F'alls of the Ohio. 

 At the latter place some large stems, over one inch in diameter, are 

 found, which are usually much altered by silicification ; but most 

 of these specimens have, on small circumscribed spots of the stems, 

 the surface characters finely preserved, and exhibit longitudinally 

 oval, funnel-shaped orifices of equal size, two millimeters in length 

 and one and a half in transverse direction. The broad interstitial 

 surface is cither smooth or decorated with obtuse papilli. Lateral 

 pores and transverse diaphragms distinctly observable. These 

 may constitute a different species from the former. 



Plate XXIII. — Fig. 4 represents silicified stems of the usual form 

 found in the drift in Michigan, and in the corniferous limestone of 

 Port Colborne ; the outer stem on the right side is altered by thick- 



