332 SYSTEMATIC PALEONTOLOGY 



ment to that of young forms of other species. There is a faint scar on 

 the hase^ which may be due to attachment in its early stages. More 

 information concerning this interesting little form will be welcomed. 



Occurrence. — JSTanjemoy Formation. Pamnnkey Eiver, Kent Co., 

 Virginia. 



Collection. — Philadelphia Academy of ISTatnral Sciences. 



ECHINODERMATA. 



Class ECHINOIDEA. 



Subclass ECHINOIDEA. 



Order SPATANGIDEA. 



Family SPATANGIDAE. 



A few fragments of the tests of spatangoid forms have been obtained 

 from the Eocene of the Middle Atlantic Slope. It is not possible to 

 determine their generic relations. A single fragment is figured (Plate 

 LXI, Fig. 1). 



Occurrence. — ISTanjemoy'' Formation. Evergreen, Va. 



Collection. — Johns Hopkins University. 



Orders DIADEMATOIDA and CIDAROIDA. 



Families DIADEMATIDAE and CIDARIDAE. 



Numerous spines belonging either to diadematoid or cidaroid forms 

 Lave been found in the Eocene deposits of Maryland but they are not 

 sufficiently distinctive to admit of generic determination. A single 

 specimen is figured (Plate LXI, Fig. 2). 



Occurrence. — Aquia Formation. Upper Marlboro, Potomac Creek. 

 Sheckels Farm near South Eiver. Severn Eiver. 



Collections. — Johns Hopkins University, Maryland Geological Survey. 



