NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
127 
ELLISINA SPICULOSA Ulrich, 1901. 
Plate 1, figs. 3-5. 
1901. Membranipora spiculosa Ulrich, Maryland Geological Survey, Eocene, p. 212, pi. 
9, figs. 3, 4. 
Description. — Zoarium adnate. Zooecia arranged in quincunx or irregularly, 
oblong, rounded and widest above, more or less produced below. Opesia large, 
normally ovate, the upper edge nicely rounded, the lower variable, taking up 
about half of the length of the zooecium. Rim thin, highest above, usually dying 
out before reaching lower extremity of zooecium. Front wall over lower half of 
zooecium, slightly depressed, covered with small granules or spines, those border- 
ing the edge projecting sharply into the opesial opening. Ooecia numerous, 
cucullate, strongly elevated, often with a tubercle or point forming the summit. 
When a zooecium is without an ooecium its place is often occupied by an elevated 
avicularium of moderate size. The avicularia are very few in number, but when 
present similar to those found in Reptoflustrella heteropora Gabb and Horn. 
Length of zooecium 0.5 or 0.6 mm. ; width, 0.25 to 0.30 mm. The specimen described 
shows a single cell differing from the rest in being closed, a convex cover, at the 
upper extremity of which a semi-circular impression is distinguishable, extending 
over the whole.” (After Ulrich.) 
The ovicell is certainly closed by the opercular valve. 
Occurrence. — Lowest Eocene (Bryozoan bed at base of A quia formation) : 
Upper Marlboro, Maryland (rare). 
ELLISINA (?) ANGUSTA Ulrich, 1901. 
Plate 1, figs. 6-10. 
1901. Membranipora angusta Ulrich, Maryland Geological Survey, Eocene, p. 213, pi. 
60, figs. 5, 6. 
Original description. — “Among the material from Upper Marlboro there are 
several specimens of a delicate Membranipora that, on account of their imperfection 
and fragile nature, it may be risky to distinguish as a new species. However, as it 
is easily recognized and may prove useful in stratigraphic studies, the writer 
has ventured to name it as above. The zooecia are shallow, elongate, elliptical, 
hexagonal, or rhomboidal, and separated except in young stages by a thin tuber- 
culated wall common to adjoining cells (that is, there is usually no depressed divid- 
ing line between the zooecia). The inner portion of the wall is much thicker than 
the outer, so that the mouths of the connecting pores, of which there are at least 
six on each side and one or two at each end, are clearly shown in a view of the 
front. Two specimens have cucullate ooecia and on all an occasional small oval or 
rounded and slightly raised avicularium may be noticed. The zooecia are about 0.4 
mm. long and 0.2 mm. wide. M. angusta apparently belongs to the M. lineata 
group of Waters.” 
M easurements. — Opesia- 
ho=0.2>0 mm. 
lo— 0.16 mm. 
Zooecia 
Lz— 0.40-0.48 mm. 
lz= 0.20-0.24 mm. 
