PAL.-EONTOLOG V. I 7 



HOUGHTONIA HURONICA, Nov. Spec. 



Globular masses, from the size of a man's fist to that of a foot in 

 diameter, with a basal scar of attachment. Tubes from two to 

 three millimeters in diameter. Interstitial spaces narrow, or tubes 

 in partial immediate contiguity without intervention of coenenchym 

 cells. Vertical crests spinulose. Diaphragms numerous, slightly 

 concave, and usually coincident with linear constrictions of the 

 tubes. By intersection of the vertical crests with these constricted 

 annular rims, the inner surface of the tubes becomes cancellated by 

 regular, square-shaped conical pits, the bottom of which is often, 

 but not always, perforated, and communicates with the cell spaces 

 of the surrounding coenenchym. 



Occurs in the Hudson River group of Drummond's Island, 

 associated with Columnaria stellata. It is likewise found abun- 

 dantly in the upper part of the Cincinnati group at Madison, 

 Indiana ; more rarely in the lower strata of the same locality. 



Plate III. — Fig. 3 is a lateral view of a specimen from Drum- 

 mond's Island, split open. Fig. 4 is a surface view of the same. 

 2 



