Foerste.] 
342 
[May 1, 
there are nineteen large and nineteen smaller septa, the latter ex- 
tending slightly more than half way down the cast. The dissep- 
iments between these septa average five to six in a length of 2 mm. 
The specimens which these casts represent were originally perhaps 
15 and 12 mm. long. 
There is found at Collinsville a species of Cyathophyllum , which 
is erect, the outlines of the sides forming an angle of about 15° at 
the base. It has twenty-seven prominent vertical septa, alternat- 
ing with twenty-seven very narrow septa, from which prominent 
spines project into the calyx. The species is about 20 mm. long 
and the diameter at the mouth of the calyx 12.5 mm. 
At Collinsville, Alabama, are also found small specimens curved 
after the fashion of C. facetus , and larger specimens resembling G. 
delator. An undoubted specimen of Streptelasma allied to Zaphren- 
tis? bilateralis , Hall, is also at hand. All these forms are scarcely 
worth describing, excepting for the fact that they show the exist- 
ence of a certain type of corals in considerable numbers in the Clin- 
ton rocks of Alabama and Tennessee. They are all casts and not 
always of the best character. 
Ptychophyllum ipomea sp. nov. 
The specimens here described are from the upper layers of the 
Clinton Group at Allen’s Quarry, east of Centreville, Ohio. The 
calyx of the best preserved specimen has a diameter of 56 mm. and 
is composed of ninety-seven septa, which have an average width of 
2 mm. near the border of the calyx, where they are contiguous ; they 
gradually narrow towards the centre of the calyx, becoming separ- 
ated ; at a distance of 6 mm. from the centre they are separated to 
the extent of about .5 to .8 mm. At the centre the lamellar septa 
of our specimens are not visible but are presumed to be more or less 
twisted as is common in the genus. At the border of the calyx the 
tops of the septa are broad and flattish, very moderately convex, 
and maintain this character for a greater or less degree for about 
10 or 12 mm. where they graduall} T assume the lamellar form. The 
calyx is broad and flat or but moderately concave for about three- 
fifths the distance from the border to the centre of the calyx, after 
which the septa rapidly descend forming a central cup about two- 
fifths of the width of the calyx in diameter, and at least 5 mm. deep, 
although on account of the partial filling up of this central depres- 
sion exact measurements cannot be given. Towards the border the 
