Maryland Geological Survey 701 



overlapped b}' adjacent ]il:ite. Tuljercles arranged in linear rows M-hich 

 make an angle of abont (JO^ witli the curved margin becoming trans- 

 verse and somewhat irregular near center of plate. Distance of rows 

 about 1.5 mm. Length of part of plate observed 90 mm., width 85 mm. 



A postero-ventro-lateral plate has also been observed which is referred 

 somewhat questionably to the same species. This plate tapers to a point 

 posteriorly; its surface is flat; one margin is nearly straight save for a 

 slight bend near apex; opposite margin is parallel to it for nearly half 

 length of incomplete specimen observed, and then bends abi'uptly at an 

 angle of 135°, continuing in a nearly straight line to the posterior ex- 

 tremity. The exterior surface is ornamented by stellate tubercles which 

 are arranged in linear rows, placed nearly transverse to length of plate 

 in posterior half, but cross it somewhat obliquely anteriorly; rows of 

 tubercles are about 1.5 mm. apart. Length of part observed GO mm., 

 width 32 mm. 



A third fragment has also been figured upon which the ornamentation 

 differs slightly. Its reference to the same species is not assured. 



These plates have been submitted to Dr. Charles E. Eastman in whose 

 honor they are named. Dr. Eastman identified them as plates of a new 

 species of Glyptaspis and comments upon the close resemblance of the 

 postero-ventro-lateral plate to plates of the genus Coccosieus. He also 

 questions whether they should be referred to the same species. The 

 similarity of the ornamentation suggests their specitic identity though 

 larger collections may prove them distinct. They are, however, tentatively 

 united under the same specific name. 



Occurrence. — Jennings Formation, Parkhead Member. Horse 

 Ridge, southwest of Hancock, West Virginia, 1600, west of Green Eidge, 

 south of Maryland-Pennsylvania state line. The reference of the specimen 

 from the latter locality to the Parkhead member is not assured. It may be 

 from the Chemung. 



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



