MARYLAND GEOLOGICAL SURVEY 743 



Genus MEMBRANIPORELLA Smitt 



MEMBRANIPORELLA ABBOTT: (Gabb and Horn) Weller 

 Plate XLVI, Fig. 4 



Escharipora abbottii Gabb and Horn, 1862, Jour. Acad. Nat. Sci., Phila. 



(2), vol. v, p. 149, pi. xx, fig. 33. 

 ReptescJiaripora marginata Gabb and Horn, 1862, Ibidem, p. 151, pi. ii, fig. 



35. 

 Membraniporella abbotti Weller, 1907, Geol. Survey of New Jersey, Pal., 



vol. iv, p. 342, pi. xxiv, fig. 13, 14. 



Description. " Zoarium encrusting or growing in bifoliate plates. 

 Zooecia elongate-subelliptical or subhexagonal in outline, usually arranged 

 in more or less regular longitudinal series and in quincunx, about 0.5 mm. 

 in length, the length about twice the width. Zooecial apertures subcir- 

 cular or subquadrate with rounded angles, sometimes rounded in front 

 and truncate posteriorly; they are situated anteriorly and occupy about 

 one-third of the length of the zocecium ; back of the aperture the surface is 

 covered by a thin, flat or slightly convex wall slightly depressed below 

 the zocecial margin, which is marked by about fourteen or fifteen lateral 

 grooves radiately arranged posteriorly, leaving a narrow, smooth area 

 along the median line, these grooves are either slit-like openings through 

 the wall or they are pierced by lines of pores, it cannot be determined 

 which from the specimens observed. Avicularia usually two to each 

 zooecium ; subovate in outline and situated one on each side of the zooecial 

 aperture, from the lateral margins of which they are directed obliquely 

 outward and backward. Ovicells present or absent, subglobular in form, 

 situated just in front of the zocecial apertures." Weller, 1907. 



Occurrence. KANCOCAS FORMATION. Noxontown Millpond, Delaware. 



Collection. Maryland Geological Survey. 



Family ESCHARIDAE 



Genus MUCRONELLA Hincks 



MTCRONELLA ASPERA Ulricli 



Plate XLVI, Figs. 8, 9 



Mucronella aspera Ulrich, 1901, Maryland Geol. Survey, Eocene, p. 221, pi. 

 Ix, figs. 17, 18. 



