290 S. AVELLER FAUNA OF THE FERN GLEN FORMATION 



The dimensions of two disk-like zoaria are: Diameter, 26 millimeters 

 and 45 millimeters; maximum thickness, 6 millimeters and 10 milli- 

 meters. 



CHILOTRTPA A1IERICAXA S. A. M. 



Plate 15, figure 3 



1881. Trematopora americana S. A. M., Journal of the Cincinnati Society of 

 Natural History, volume 4, page 312, plate 7, figures 5-5a. 



Description. — Zoarium consisting of more or less irregular, subcylin- 

 drical branches, 2 to 10 millimeters in diameter, the smaller ones some- 

 times solid, the larger ones with an axial cavity. Zocecial apertures 

 arranged irregularly, ovate in outline, their margins slightly elevated in 

 a thickened lip; lunarium usually rather obscure, the intervals between 

 the apertures three or four times the width of the apertures themselves. 

 Surface of the zoarium elevated at intervals in rather large, undefined 

 monticules, upon which the zocecia are more widely scattered. 



Remarks. — Miller's species, Trematopora americana, was described 

 without mention of the internal characters, and the present Fern Glen 

 examples are identified with it on the strength of the external features 

 alone. In these characters the Fern Glen specimens agree very closely 

 with Miller's figures and description. The species is clearly not a mem- 

 ber of the genus Trematopora. It is one of the Fistuliporidae and seems 

 to correspond in all essential features with the genus ChiJotrypa. 



CTSTODICTTA LIXEATA Ulrich 



Plate 15, figure 4 



1884. Cystodictya lincata Ulrich, Journal of the Cincinnati Society of Natural 

 History, volume 7, page 37, place 2, figures 4-4c. 



Description. — Zoarium bifoliate, consisting of strongly compressed, 

 sharp-edged, bifurcating branches. Surface of each face of the branches 

 a little convex, with low, rounded, longitudinal ridges, between which the 

 zocecial apertures are arranged in from seven to nine longitudinal lines; 

 transversely the zocecial apertures are arranged in more or less regular 

 oblique rows; the longitudinal ridges are most conspicuous and most 

 continuous in the central portion of the branches; laterally they become 

 more or less discontinuous and consist rather of a series of depressed 

 nodes upon the inner slopes of which are located the zocecial apertures; 

 outside of the outermost zocecia is a narrow, smooth, or finely striated, 

 non-poriferous margin; zocecia with distinct lateral lunaria, which give 

 to the apertures a depressed pyriform outline; on either side of the 



