OLDKK ro'lOMAc Ol' \ IKdlMA AND MAHVLAND. 573 



i.s confined to llie Kappaliannock horizon, its prosoncc donotes an 

 Annulol oi- Kappaliannock ago for the hods containing it. Tliis appears 

 to have boon .sotnewliat sniaHor tlian the one figured in Monograph X\\ 

 11 is given in PL CXIX. Fig. 8. It wa.s coUected by Mr. liibbins for 

 the Marvhmd (loological Hnr\-oy in August, lS9i), and bears th(> number 

 5312 of that survey. 



KOSSIl. I'l.AMS rltdll l.dCIST OK POI'l.Alt POINT. 



fPI. 1>XXX, .\.,. 10.1 



Locust or Poplai- Point has yielded to the collections five or six- 

 rock fragments witli plant mattoi'. The iwk material is an ash-gray, 

 rather aronaeeous shale, stated on th(> laliols to be Patapsco in age. 

 This clay has a good many bits of carbonized vegetable mattei' which 

 are not determinable. Two specimens, however, are small coik^s that 

 are most probably cones of Al}irotaxopsifi expmi.sa. but which can not 

 be determined positively as such. The evidence from these is not 

 sufficient to locate the horizon of tlu> plants. This Athrotaxopsis is, 

 in th(- ^urginia localities, most characteristic of the Rappahannock 

 horizon. 



The material containing these impressions was collected by Mr. 

 Bil)])ins in Jtily, 1897, for the Maryland Geological Sm-vey. It is all 

 under one label marked M. G. S., Xo. 5316. A single .specimen col- 

 lected in August, 1899, ami marked M. G. S., Xo. 5315, shows nothing 

 determinable. 



Fossil, IM.A.VTS HiOll (atAVS IIII.I,. 



[PI. LXXX, No. «.] 



A few plants are credited on the labels to Grays Hill, Cecil County, 

 formation Patapsco, collected l)y Mr. Bil)l)ins for the Maryland Geo- 

 logic:d Survey in August. 1899. The rock mateiial is much like that 

 from Vinegar Hill. The determinable fossils are 1 specimen of Podo- 

 zamites distantinervis Font, and 2 of Sphenolepidium - Stcrnherginnum 

 densifolium Font. They pr()bal)ly belong to the former. The plants 

 do not suffice positively to determine whether the Gravs Hill strata 

 correspond to the Rappahannock or to the Aquia Creek member of 

 the Virginia Potomac. 



