Foerste.] 
344 
[May 1, 
border of the periphery, these diaphragms bend upward and then 
outward to the periphery of the stem, the various diaphragms here 
either interfering or becoming increased by the addition of short 
dissepiments so that the peripheral portion of the stem is some- 
what vesciculose. 
This species is rare at Soldiers’ Home, near Dayton, Ohio, and 
at Allen’s Quarry, west of Centreville, Ohio. It is represented, 
together with Illcenus Daytonensis , from the Clinton of Yellow 
Springs, Ohio, in the Cabinet of Columbia College. 
Our specimens more closely resemble the types and other speci- 
mens gathered from the locality where they were found than they 
do the published figures from the Niagara of New York. 
Some of the specimens at Ludlow Falls are more rugosely 
wrinkled and mark an advance toward the Dipliyphyllum rugosum 
type. 
Streptelasma Hoskinsoni, sp. nov. 
(plate ix, figs. 1-4 ; perhaps 5-6.) 
This species is quite common at Brown’s Quarry, west of New 
Carlisle, Ohio. The type specimen belongs to my own collection ; 
all the other forms here described to that of Prof. W. S. Hoskin- 
son. Its form is simple, inversely conical, tapering in the more 
typical forms quite regularly, with a few transverse annulations. 
The annulations are formed by a more or less sudden constriction 
of the mouth of the calyx, the continuation of the coral then be- 
ginning again at a slightly decreased diameter. In one specimen 
there are no annulations present and the coral tapers gradually 
throughout. In other specimens these constrictions occur fre- 
quently and irregularly. The last form figured under this species 
on our plate probably does not belong to this series, but it is im- 
possible to distinguish it from an exterior view alone, from the 
shorter, less annulated forms. 
The polyp is always slightly curved towards the base, the greater 
convexity being on the side of the apertural gap. The other side 
may be either gently concave or almost straight, except near the 
base. In some specimens the base of the polyp only is curved, 
the potyp soon after becoming erect. The exterior surface of the 
polyp walls is very regularly ribbed longitudinally, the ribs be- 
ing usually gently convex, but sharply defined, and correspond- 
ing in number to the septa within. The septa vary from forty 
