OHIO STATE ACADEMY OF SCIENCE. Y5) 
tances, sometimes much apart. Inner surface of tubes 
smooth, inural pores small, not numerous, spaces between 
diaphragms filled with large and small cysts of unsyste- 
matical arrangements, which gives this species a most pecu- 
liar character. No spines or squamz can be detected; 
every effort of that kind organized into a labyrinthical 
spongeous texture. External growth in convex masses. It 
is thus far known the only Favosites of such organization. 
— Corniferous Limestone, Ohio Falls. 
Chonetes cinctatus, sp. nov. 
(Fig. 1. Enlarged.) 
Shell small, oval, gibbous; length two-thirds of its 
breadth; lateral margins curving in, so as to give develop- 
ment of two large ears, being quite mucronate, which ter- 
minate the hinge. Ventral valve quite convex without a 
mesial sinus in front; ears rounded and well projected; 
Fic. 1. Chonetes cinctatus. 
area narrow; cardinal margin with two oblique spines on 
each side of the umbo. Surface ornamented with 12 stout 
rounded strie, which gradually disappear in the banded 
structure of the shell, imbricating it in squamous manner 
up to a small area around the umbo. This imbrication is 
very irregular, more squamous and has been caused by the 
overlapping of the mantel of the animal, building its shell re- 
