38 The Paleontologist. [June 10, 



Ptilodictya cleavelandi, sp. nov. James. 



Polyzoary, as far as observed, consisting of slightly oval, or flattened 

 two-edged fronds, about half a line wide, and i^ to J^ an inch long, 

 giving off short lateral branches, varying from nearly right to acute 

 angles, from half a line to one line apart, arranged, generally, in an al- 

 ternating manner, but in some cases opposite to each other. Fronds 

 celluliferous on both sides, with five or six rows on each face of the main 

 stem, of oval, or sub-circular cells, arranged alternately, and four or five 

 rows on the branches. No elevated or dividing line at the lateral mar- 

 gins of the fronds, as in some other species of this Genus. Four or five 

 cell apertures, in the space of half a line, measuring diagonally across 

 the frond. The best preserved specimens show the cell walls as distinct, 

 and a depressed, sinuous line between, with the margins of the cell 

 mouths slightly raised. Internal structure not observed. 



This species bears some resemblance to Pt. shafen, Meek (Pal. of O. , 

 vol. i., p. 69, pi. 5), but differs materially in the rounded, wo;z-striate, 

 instead of flat, sharp striate edges of the fronds of that species ; and the 

 single depressed line between the cell apertures, instead of a striate sur- 

 face. 



Named in honor of W. P. Cleaveland, Esq. , who has devoted much 

 time to making microscopic sections and slides of the corals and allied 

 forms of the Cincinnati Group. 



Found at Cincinnati and other localities in the Cincinnati Group, be- 

 tween 80 and 200 feet above low water mark of the Ohio river. 



Ptilodictya kentuckyensis, sp. nov. James. 



Polyzoary of this species, so much as observed, a minute, flattened, 

 two-edged frond, springing from a sharply-pointed base, and bifurcating 

 at an angle of about 45 degrees, less than half a line above ; each divi- 

 sion cfivincf off an outward lateral branch about half a line farther above ; 

 stems about half a line wide, slightly raised in the middle, and rounding 

 gently from one edge to the other, with three or four rows of long, oval- 

 shaped pores, of w^hich three occupy the space of half a line, measuring 

 their longer diameter (longitudinally). Margins of cell walls thin ; cell 

 mouths not raised. An indistinct depresssed line between some of the 

 pores. Height from the base to a point in the middle, between the two 

 divisions, a little over one line ; breadth, measuring from the outer mar- 

 gins, about the same, forming, in outline, two sides of an equilateral 

 triangle. 



Locality : Bank of the Ohio river, opposite the lower part of Cincin- 

 nati, about 10 or 15 feet above low water mark, in a bed of blue shale. 

 Cincinnati Group, Lower Silurian formation. 



Ptilodictya clintonensis, sp. nov. James. 



Polyzoary a straight, convex, two-edged, unbranched frond, commenc- 

 ing at a pointed, cylindrical base, widening and flattening above; elliptical 

 in transverse section at the upper part. Cells arranged in longitudinal 



