MARYLAND GEOLOGICAL SURVEY 209 



CLASS CRINOIDEA 



Order GAMER ATA ' ' 



Family RETEOCRINIDAE 

 Genus RETEOCRINUS Billings 



KETEOCRINUS ? sp. 

 Plate XXXVII, Fig. 5 



Description. Small plates showing six or seven rays are not uncommon 

 on the surface of the thin-bedded Frederick limestone. These are of 

 echinoderm nature, but whether cystid or crinoid cannot be determined. 

 They appear most like the minute pieces forming the pliant integument 

 of the interbrachial areas in such crinoidal genera as Reteocrinus. 



Occurrence. FREDERICK LIMESTONE. In the vicinity of Frederick, 

 Maryland. . 



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



Order INADUNATA 



Family CYATHOCRINIDAE 



Genus CARABOGRINUS Billings 



CARABOCRINUS sp. 



Plate XLI, Fig. 10 



Description. Associated with the small plates of the cystid Caryo- 

 cystites in the lowest bed of the Chambersburg limestone are larger, 

 strongly marked plates of a crinoid. These bear the characteristic mark- 

 ings of the genus Carabocrinus, and as such plates are known only from 

 this division of the Chambersburg limestone an illustration of one has 

 been given on pi. XLI as a characteristic, although unnamed fossil. 



Occurrence. CHAMBERSBURG LIMESTONE (Caryocystites bed). Fort 

 Loudon south to Blue Spring, Franklin County, Pennsylvania. 



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



