358 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Occurrence. — Vicksburgian (“ Chimney rock” of Marianna limestone): One 
mile north of Monroeville, Alabama (abundant). 
Vicksburgian (Red Bluff clay) : Seven and one-half miles southwest of Bladen 
Springs, Alabama (rare). 
Cotypes. — Cat. No. 64271, U.S.N.M. 
SCHIZOMAVELLA LONGIROSTRIS, new species. 
Plate 85, fig. 13. 
Description. — The zoarium is free, bilamellar, very small; the two lamellae are 
easily separable. The zooecia are elongated, distinct, oval; the frontal is convex 
and formed of a tremocyst with large pores. The aperture is orbicular or trans- 
verse; the anter is large and semilunar; the rimule is wide and concave. The ovicell 
is globular and salient; its orifice is always closed bv the operculum. The median 
avicularium is long , salient, provided with a pivot and a long triangular beak. 
Measurements .- — Aperture 
[ ha=0.10 mm. 
\la= 0.12 mm. 
Zooecia 
L. s=0.65-0.80 mm. 
fe=0.40mm. 
Affinities. — -We possess only a few small specimens of this species, and it has 
therefore been impossible for us to make a careful study of it. It appears to present 
some interesting peculiarities in its ovicell and in the disposition of its large 
avicularium ; but it is necessary to await more material. 
There is a similar recent species, Schizoporella longirostrata Hincks, 1882, but 
its avicularium is not median. 
Occun'ence. — Vicksburgian (Red Bluff clay) : Red Bluff, Wayne County, Mis- 
sissippi (rare). 
Holotype. — Cat. No. 64264, U. S. N. M. 
SCHIZOLAVELLA , 1 new genus. 
The ovicell is closed by the operculum. The operculum bears a variable 
rimule. The frontal is a tremocyst. There are two lateral avicularia. 
Genotype. — Schizoporella vulgaris Moll, 1803. 
Range— Rupelian — Recent. 
This genus differs from Schizomavella only in the lateral position of the avicu- 
laria and in the muscular attachments of the operculum, which are more distant 
from the border. 
The functions of the avicularia seem to be multiple; but they are not well 
known. The generic divisions based on these organs always present a relative 
uncertainty which only further studies can eliminate. 
The fossil species of this same genus are : 
Schizolavella ( Eschara ) phymatopora Reuss, 1869. 
Schizolavella ( Lepralia ) schizostoma MacGillivray, 1895. 
1 Zar=abbreviation of “lateral avicularia.” 
