748 SYSTEMATIC PALEONTOLOGY 



Thus the posterior portion of the shell in fully developed individuals 

 represents H. squamosus Gabb, the anterior portion H. onyx Morton. 



The species is widely distributed in the Monmouth of Prince George's 

 County, but it is exceedingly brittle and difficult to separate from the 

 matrix. 



Occurrence. MATAWAN FORMATION. Ulmstead Point, Anne Arundel 

 County. MONMOUTH FORMATION. Brightseat, Brooks estate near Seat 

 Pleasant, Friendly, 1 mile west of Friendly, Prince George's County. 



Collection. Maryland Geological Survey. 



INCERTAE SEDIS 



Family SERPULIDAE(P) 



Genus ORNATAPORTA n. gen. 

 Type. Ornataporta marylandica Gardner n. sp. 



Tube small, tapering gradually toward the aperture ; operculum reticu- 

 lately sculptured. 



ORNATAPORTA MARYLANDICA n. sp. 

 Plate XLVII, Figs. 16-19 



Description. Tubes rather small, usually more or less arcuate, slightly 

 tapering, smaller end of tube in two individuals obliquely truncated at an 

 angle of about 30 ; truncated surface in cast subcircular to broadly 

 elliptical in outline, elaborately sculptured both radially and concentri- 

 cally; radials fine, well rounded lirae, diverging in all directions from a 

 strongly eccentric nucleus, possibly a little coarser on the shorter side, 

 number -more than doubled near the margin by intercalation and bifur- 

 cating; concentric sculpture in part incremental in character, two to five 

 prominent growth stages usually visible; very fine and crowded thread- 

 lets also developed, not overriding the radials but closely dissecting the 

 interradials. 



Dimensions. Length, 18.6 mm.; diameter of larger end, 6 mm.; 

 diameter of smaller (operculum-bearing) end, 4.5 mm. 



The nature of these extraordinary impressions is very obscure. When 

 the first was found it was thought that the association of the tube with 

 the sculpture might be fortuitous, but the discovery of a second similarly 



Etymology: Ornata. elaborate; porta, a door. 



