Maryland Geological Survey 289 



wide, tapering at the lower end to a pointed base. Entire zoarium 

 consists, as in all simple species of the genus, of narrow, oblong, quadrate 

 zocecia arranged in a longitudinal series. Counting longitudinally, 8 

 zooocia in 2 mm. and transversely about 12 rows of zocecia in a frond of 

 2 mm. width, a single zooecium thus being about .25 mm. in length and .17 

 mm. wide, or the length and width being to each other as 3 is to 2. 



The simple narrow zoarium and the shape of the zocecia will distinguish 

 this form from described species. Ptilodictya angusia (Hall)^ has a 

 similar method of growth, but the measurements given indicate that it 

 has much larger zocecia and it may indeed not be a Ptilodictya. Plilo- 

 dictya yladiola Billings ^ from Anticosti is probably a close relative, but 

 the zoarium of that species is usually curved and the zocecia are more 

 elongated, their length being twice their width. 



Occurrence. — Helderberg Formation, Keyser Member. Cumber- 

 land. 



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



Family STICTOPORELLIDAE 



Genus STICTOPORA Hall 



Stictorora ? rarillosa Hall 

 Plate LI, Figs. 12-li 



Stictopora papulosa Hall, 188.3, Kept. State Geol. N. Y. for 1882, pi. xiil, figs. 



12 and 13. 

 Stictopora papillosa Hall and Simpson, 1887, Pal. N. Y., vol. vi, p. 37, pi. xiii, 



figs. 12 and 13; pi. xxiiia, fig. 16. 



Description. — A single specimen from the New Scotland limestone at 

 Kreigbaum, Maiyland, exhibits all of the characters of this neat little 

 species as figured by Hall. On account of the preservation, the internal 

 characters of the species have not been studied yet, so that it must still 

 be referred to as above. Its external features are sufficient for its easy 

 recognition. 



^ Escharopora (Ptilodictya) angusta Hall, 1883, Trans. Albany Institute, vol. 

 X, p. 621 (Abstract, 1879, p. 6). 



'Ptilodictya gladiola Billings, 1866, Catal. Sil. Foss. Anticosti, p. 10. 

 19 



