84 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
Each distal wall and the distal half of each lateral wall with a row (6-8) of one or 
two pored rosette plates [septulae]. A longitudinal series of parietal muscles is 
placed on each side between the cryptocyst and the covering membrane. 
Genotype.—Microporina {Cellaria) borealis Busk and Microporina ( Micropora ) 
elongata Hincks, 1880. Range: Campanian, Recent. 
Homalostega amphora Marsson, 1887, from the Campanian of Rugen, also 
belongs to this genus. 
Genus CORYNOSTYLUS Canu and Bassler, 1919. 
1919. Corynostylus Canu and Bassler, Geology and Paleontology of the West Indies, Bryozoa, 
Publication of the Carnegie Institution of Washington, No. 291, p. 86. 
No ovicell. The opercular valve articulates on two condyles. The zooecia are 
club shaped and provided with a gymnocyst. The zoarium is articulated. 
Genotype.—Corynostylus labiatus Canu and Bassler, 1919. Miocene. 
This genus has no recent equivalent but its structure is easy to interpret. 
The two condyles serve as a hinge for the strongly chitinized opercular valve. The 
lower part of the opesium placed below served evidently as passage for the opesiular 
fibers attached to the ectocj-st. The deep cavity of the cryptocyst served as a 
hydrostatic apparatus for the entrance and exit of the polypide. Like most of 
the articulated genera, the zoarium in this one probably was fastened on large 
mobile, algae. 
CORYNOSTYLUS LABIATUS Canu and Bassler, 1919. 
Plate 2, figs. 11-13. 
1919. Corynostylus labiatus Canu and Bassler, Geology and Paleontology of the West Indies. 
Bryozoa, Publications Carnegie Institution of Washington, No. 291, p. 87, pi. 2, figs. 11-13. 
Description. —The zoarium is articulated and formed of long regular segments. 
The segments are compressed, bilamellar, formed of three longitudinal rows of 
zooecia on each side. The zooecia are elongate, oval, distinct, rounded in front, 
narrowed behind and are provided with a convex gymnocyst with large pores; 
the mural rim is thick, regular, granular. The opesium is elongate, oval, pro¬ 
vided with a proximal, salient lip placed between two rounded opesiular indenta¬ 
tions. The two condyles are quite salient. The cryptocyst is deep and smooth. 
,, , ~ ho = 0.12 mm. 
Measurements .—Opesia 7 . ,. 
' \ to = 0.10 mm. 
Zooecia 
Lz = 0.50 mm. 
lz = 0.20 — 0.28 mm. 
Affinities. —The first zooecium of each segment is radicular; it gives rise to 
three polypidian zooecia. 
Occurrence.— Lower Miocene (Bowden horizon): Cercado de Mao, Santo Do¬ 
mingo (common). 
Holotype. —Cat. No. 68514, U.S.N.M. 
CORYNOSTYLUS ELLIPT1CUS Canu and Bassler, 1919. 
Plate 2, figs. 8-10. 
1919. Corynostylus ellipticus Canu and Bassler, Geology and Paleontology of the West Indies, 
Bryozoa, Publications of the Carnegie Institution of Washington, No. 291, p. 87, pi. 2, 
figs. 8-10. 
Description. —The zoarium is articulated. The segments are formed of two 
longitudinal rows of zooecia placed only on one side of the zoarium. The zooecia 
