MARYLAND GEOLOGICAL SURVEY 211 



half miles northeast of Fort London, Pennsylvania. Eden shale of New 

 York and the Ohio Valley. 



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



Family DENDROCRINIDAE 



Genus MEROCRINUS Walcott 



MEROCRINUS sp. 



Plate LIII, Fig. 5 



Description-. Only stem segments of this crinoid have been found in 

 the upper Martinsburg shale, but the genus itself is so characteristic of 

 the Trenton and Eden formations that it was thought advisable to figure 

 an example as a characteristic fossil. It is possible that the segments 

 here illustrated will be found to belong to the only known Eden species, 

 M. curtus Ulrich, from the Cincinnati region. 



Occurrence. MARTINSBURG SHALE- (Eden division). Jordans Knob, 

 one and one-half miles northeast of Fort Loudon, and other localities in 

 southern Pennsylvania, and in the sandy debris on the west slope of 

 Rickard Mountain, Washington County, Maryland. 

 Collections. U. S. National Museum. 



CLASS STELLEROIDEA 



Family HUDSONASTERIDAE 



Genus HUDSONASTER Stiirtz 



HUDSONASTER CLARKI n. Sp. 



Plate LIII, Fig. 8 



Description. This new species is based upon two specimens preserved 

 as a mold in sandy shale and exhibiting the actinal side. The species is 

 closely related to H. matutinus (Hall) from the Trenton, and is indeed 

 probably descended from it, but the Eden form differs in having coarse 

 tuberculations on the axillary plates and more slender and more regu- 

 larly tapering arms. Further differences will no doubt be detected when 

 better specimens are found, but the above seem sufficient to discriminate 

 the species. 



