NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
47') 
The recent species of this genus are: 
Mucronella { Lepralia ) peachi Johnston, 1847. 
Mucronella { Lepralia ) ventricosa Hassall, 1841. 
Mucronella {Lepralia) variolosa Johnston, 1S47. 
Mucronella teres Hincks, 1881. 
Mucronella crozetensis Waters, 1904. 
The known fossil species are : 
Mucronella ( Lepralia ) hornesi Reuss, 1865. Oligocene of Germany. 
Mucronella {Lepralia) grotriani Reuss, 1865. Oligocene of Germany. 
MUCRONELLA PATENS, new species. 
Plate 62, fig. 10. 
Description. — The zoarium incrusts shells. The zooecia are distinct, wide, 
hexagonal; the frontal is convex, and surrounded by a double row of small areolae, 
much crowded. The peristome is salient, wide, its proximal portion is a very 
salient and erect mucro; the lyrula is small and triangular. The ovicell is hyper- 
stomial and is placed on the distal zooecium; it is small, globular, salient, smooth; 
its orifice is placed just at the level of the mucro. 
Measurements. — Peristomice 
| =0.10 mm. 
|7pe=0.15 mm. 
Zooecia 
[713=0.60-0.70 mm. 
[73=0.75 mm. 
Affinities. — This species is quite well characterized by its great zooecial width ; 
all the known species have some elongated zooecia. 
Occurrence. — Middle Jacksonian (Castle Havne limestone) : Wilmington, North 
Carolina (rare). 
Holotype. — Cat. No. 64139, U.S.N.M. , 
MUCRONELLA GRANULOSA, new species. 
Plate 62, figs. 8, 9. 
Description. — The zoarium incrusts bryozoa. The zooecia are distinct, little 
elongated, hexagonal; the frontal is convex, surrounded by a line of small areolae 
and formed by a regularly granular pleurocyst. The peristome is thin, sharp, little 
salient; it bears on the anter 4 to 6 spines and on the poster a lamellar mucro, 
oblique, very prominent and partially hiding the apertura; a small lyrula and two 
very small cardelles are visible at the base of the peristomie. 
Measurements. — Peristomice 
\hpe=0.0& mm. 
(7/>e=0.14 mm. 
Zooecia 
\L?= 0.51 mm. 
1/3=0.40 mm. 
Affinities. — This species is very elegant; it is rather rare that the elements of 
the pleurocyst are deposited with such regularity; however, this phenomenon exists 
in Mucronella variolosa Johnston, 1847. A single specimen has been found, in- 
complete, for the ovicell is wanting, but it appears interesting to us on account of 
its elegance alone. 
O ccurreivce. — Lower Jacksonian (Mooclys marl) : Jackson, Mississippi (very 
rare). 
Holotype. — Cat. No. 64138, U.S.N.M. 
