Makyland Geological Survey 227 



This species is distinguished from others in the fauna by its numerous 

 closely set, elevated, conical monticules and by its internal structure. It 

 has been observed at one horizon only in Maryland, being found in a coral 

 reef at the base of the Keyser member, where it is locally abundant. 



Occurrence. — Heldeeberg Formation, Keyser Member. South slope 

 of hill 4400 feet in an air line north 10° east of Signal Station on Warrior 

 Mountain. 



Colleciion. — Marjdand Geological Survey. 



Family IDIOSTKOMIDAE 



Genus IDIOSIROMA 



Idiostroma sp. 



Description. — A species of the genus Idiostroma is present in the 

 Stromatopora reefs of the Helderberg, but satisfactory sections showing its 

 intimate structure have not been obtained. It has cylindrical branches 5 

 to 10 mm. in diameter. 



Occurrence. — Helderberg Formation, Keyser Member. Kear Cum- 

 berland. 



Collection. — Maryland Geological Survey. 



ECHINODERMATA 



Subbranch PELMATOZOA 



Class CYSTOIDEA 



Family CAMAROCYSTIDAE 



Genus CAMAROCRINUS Hall 



Camarocrinus stellatus HalP 

 Plate XXXI, Figs. 1-5 



Camarocrinus stellatus Hall, 1879, 28tli Rept. N. Y. State Mus. Nat. Hist., 

 Mus. ed., p. 207, pi. xxxv, figs. 1-8; Extract, 4°, 1880, p. 5, pi. xxxv, figs. 

 1-8, pi. xliv, figs. 1-5. 



Camarocrinus stellatus Schuchert, 1904, Smith. Misc. Col., vol. xlvii, pt. ii, 

 No. 1482, pp. 269, 270. 



'This is now known to represent a part of a crinoid and not a cystid. 



