BULLETIN OF THE LABORATORIES 
I 68 
This species is seen to be quite variable, but there is no difficulty 
at all in tracing the connection of the different forms in any collection 
which contains a large number of specimens in a good state of preser- 
vation. As might be expected, its distribution is also quite wide, ex- 
tending from New York to Ontario and Ohio, and being found both in 
the Niagara shales and in the Clinton Group. 
Locality and position. Brown’s Quarry, Soldiers’ Home Quarries, 
Centreville, Fair Haven, Todd’s Fork, Clinton Group. 
FISTULIPORlDyE, Ulrich. 
This family is closely allied to the Cystodictyonid(B, from which it 
differs in the absence of non-poriferous margins and in having no sec- 
ondary deposit obscuring the presence of the interstitial cells, or at 
least, when present, being quite superficial. 
Genus LICHENALIA, Hall. 
Zoaria composed of a single layer of cells, the epithecal side be- 
ing concentrically wrinkled, the wrinkles being supplemented by sec- 
ondary finer concentric stri^; when the epithecal membrane is trans- 
lucent, the bases of the cells may be frequently seen in the form of 
short, radiating strise. Cells with a crescentic lip at the aperture 
which is continued into the tube of the cell in the form of two longi- 
tudinal inflections of the cell walls. Interstitial cells always present, 
separating the cells. 
XVI. Lichenalia concentrica. Hall. 
{Plate XVH, Fig. lo.) 
No specimens of this species have been found in my own collec- 
tions, but it is represented by several specimens in the' cabinet of Dr. 
L. B. Welch. The following short description of this species is there- 
fore added. 
Zoaria forming circular flattened expansions, often 130 mm, in di- 
ameter, celluliferous on one side only, the arrangement of the cells 
being disturbed in some varieties by the presence of macul^; Cells 
