OF DENISON UNIVERSITY. 
79 
ly elevated peristome, about o. i mm. in diameter, and 0.3 mm', apart; 
eleven in 5 mm. They are arranged so that one is opposite a lateral 
branch and one between.” 
‘‘This species though closely allied to several English and Seotish 
species is nevertheless quite distinct. Of American forms, P. Vinei 
seems to be closer than any other, but differs in being smaller and in 
having three zooecia where this has two.” 
The Ohio specimens present more variation in the strength of the 
midribs than the original Kentucky and Iowa examples. While the 
average is about as given above, in some the width is only 0.5 mm., 
and in others nearly o. 8 mm. 
Formation and locality : — The Ohio examples are from the Cuy- 
ahoga shales at Richfield and Lodi. The types are from the Keokuk 
group at King’s Mountain, Kentucky, and Keokuk, Iowa. 
PiNNATOPORA TENUIRAMOSA. Ulrich. 
Pinnatopoi'a tenuiramosa, Ulich, 111. Geoi. Surv.vol. VIII, pi. LXVI, fig. 7. (In press.) 
My remarks on this species in the above work read as follows : 
“Of this species only the reverse aspect has been observed. The best 
fragment seen preserves a portion of the primary branch about i cm. 
long. This is between o. 6 or o. 7 mm. wide, and on one side throws 
off three, on the other only one secondary branch, varying in width 
from o, 5 to o. 6 mm. The primary and secondary lateral branches or 
pinnae, diverge at angles of from 70 to 80°, are slender, about one- 
third as wide as the principal branches, from less than i.o to nearly . 
3.0 mm. long, those proceeding from the primary branch the longest, 
with twelve or thirteen given off on each side in the space of i cm. 
Surface of both branches and pinnae marked with fine distinct longitu- 
dinal striae.” 
Since the above was written I have collected a good suite of speci- 
mens at the original locality. Like the type specimens none of these 
show the obverse face in a satisfactory manner. As near as can be 
determined, that aspect must resemble that of P. Vinei very closely, 
and it is not impossible that better specimens of both species than I 
have yet seen may show the propriety of uniting them under one name. 
All the specimens that I have referred to P: tenmramosa have twelve 
or thirteen pinnae on each side in 10 mm. Those referred to P. Vinei 
are equally constant in having nine or ten in the same space. P. sim- 
