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BULLETIN OF THE ■ LABORATORIES 
mens is not mentioned, this can not assist in the identification of our 
specimens. However the branches of our specimens are not evidently 
tortuous, nor are the fenestrules elongate hexagonal in form. 
Dictyonema splendens^ Billings^ is said to have ‘ ‘ longitudinal 
stems about one-third of a line wide, and about their own width dis- 
tant from each other. There are five or six longitudinal stipes in the 
width of two lines,” a very suggestive mathematical problem. Giving 
it a fair interpretation, there are 5 or 6 branches instead of 8 in a width 
of 2 lines, and the branches are probably somewhat broader than in 
our own specimens. 
In neither case is any mention of the cells made. All three forms 
may eventually prove to belong to the same species. At present, 
however, our form appears a well defined species with close and nar- 
rower branches than any hitherto described. 
Locality and position. Soldiers Home, near Dayton, Ohio. Clin- 
ton Group. 
II. Dictyonema scalariforme, sp. n. 
(Plate VIII, Figs. 28, 29.) 
Frond infundibuliform. Branches of medium size, from once to 
twice their own width distant from each other, dividing dichotomously 
and connected by transverse bars or dissipiments one-fourth or one- 
third their width. The dissepiments are- stationed at unequal distances 
from each other, varying from once to twice the distance between the 
branches, and leaving quadrangular or oblong fenestrules between the 
same. The celluliferous side of the frond has not been seen ; in places 
however where the frond has been abraded the position and the fre- 
quency of the cells is distinctly shown. Judging from this, they are 
placed in a single row along the middle of each branch ; there are 
about 13 cells in a length of 5 mm ; these cells seem to have an ob- 
lique upward direction, consecutive cells leaning upon those in front 
of them, thus forming a narrow ridge or keel ; at their tips the cells 
seem to have become more or less free, and to have developed circu- 
lar apertures. Non-celluliferous face striated obliquely by short, curved 
striae suggesting twisted strands. 
Frond here described, a flabellate fragment, 40 mm. long and 35 
mm. broad. From 10 to 12 branches occupy a width of 10 mm, and 
from 10 to 13 dissepiments occupy the same distance in length. The 
