OF DENISON UNIVERSITY. 
107 
exterior crust, these striae often appear as radiating series of papillae, 
especially prominent and distinct near the anterior and lateral margins. 
Locality and position. Soldiers’ Home Quarries, Fauver’s Quarry, 
Centreville. Clinton Group. Also in New York and Tennessee. 
/ 
GRAPTOLITID^. 
I. Dictyonema pertenue, . . . . n. sp. 
II. Dictyonema scalariforme, . . . . n. sp. 
Genus DICTYONEMA, Hall. 
I. Dictyonema pertenue, sp. n. 
{Plate VHI, Figs. 27, a, b.) 
Frond infundibuliform, composed of numerous slender branches 
connected at intervals by fine transverse dissepiments, thus forming a 
fenestrated expansion. The branches are more or less cylindrical in 
form, about .23 mm. broad, and from 1.3 to 2 times their own width 
distant from another ; they increase by dichotomous division, adjacent 
branches are parallel, about 9 branches occupying a width of 5 mm. 
The dissepiments are very fine, about .025 mm. thick; owing to their 
fineness they can not be readily discovered in all parts of the fronds, 
nor can their arrangement be accurately determined, but on an aver- 
age they seem to be about i mm. or slightly less apart. Non-cellulifer- 
ous face marked by strong, short, curved striae, suggestion the appear- 
ance of twisted strands. The celluliferous face has not been seen, 
however abraded specimens frequently leave impressions of the cells 
in the rock from which the following characters are drawn up. Cells, 
circular at their apertures and protruded from the surface of the frond, 
arranged in a single, straight series along the middle of the branches. 
The cells are about .18 mm. in diameter, and a little more than their 
own width apart, about 12 cells occupying a length of 5 mm. The 
frond from which this description was prepared is a flabellate fragment 
23 mm. in length. 
The name signifies very slender. 
DictyoneiJia pergracile., Hall and Whitfield., is described as a species 
in which the branches do not exceed .5 mm. Our specimens are- orily 
half that size, but since the minimum width in the Kentucky speci- 
