Maryland Geological Survey 381 



fenestrule, while in the present species an average of four is counted in 

 the same space. 



The preservation of the material at hand is not satisfactory as to finer 

 details of structure. It is believed, however, that better specimens may 

 show other differences between F. pliilia and F. cumberlandica besides 

 those indicated above. 



Occurrence. — Heldehberg Formatiox, Keyser Member. Cash 

 Valley, Devil's Backbone. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Fenestella niiLiA Hall 



Plate LI, Figs. 6-S 



Fenestella Philia Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. xx, figs. 9-11. 

 Fenestella Philia Hall and Simpson, 1887, Pal. N. Y., vol. vi, p. 50, pi. xx, 

 figs. 9-11. 



Description. — Zoarium of slender, rounded, smooth branches, from 12 

 to 16 in the space of 5 mm. Dissepiments slender, with 9 in 5 mm. 

 Fenestrules quadrangular. Branches angular and marked by a line of 

 nodes along the center on the cellulif erous face. Zooecial apertures small, 

 circular and in two ranges, with three in the space of one fenestrule. 



Occurrence. — Helderberg Formation, New Scotland Member. 

 North foot of Moore Knob, Washington County. 



Collection. — U. S. National Museum. 



FeNESTELLA ? IDALIA Hall 



Plate LII, Figs. 9-11 



Fenestella idalia Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. xxl, figs. 6-9. 

 Fenestella idalia Hall and Simpson, 1887, Pal. N. Y., vol. vi, p. 52, pi. xxi, 

 figs. 6-9. 



Description. — In Maryland only the non-celluliferous side of this 

 species has been noted, but this portion of the zoarium, however, is easily 

 distinguished by the rounded, compactly arranged, rather broad branches, 

 marked by 3 to 5 striations and by the subquadrangular fenestrules. The 

 dissepiments are very' slender, with 6 to 9 in the space of 5 mm. 



