NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
523 
of avicularia with semicircular mandibles. The zooecia are distinct, elongated, 
separated by a furrow of little depth; the frontal is smooth, convex, ornamented 
with some lateral areolae. The peristome is large, salient, very thick, and bears two 
small lateral avicularia; the peristomice is orbicular; it has no peristomie, visible 
exteriorly. The spiramen is little distant from the peristomice ; it is elongated into 
the form of a buttonhole. 
Measurements . — Peristomice 
jhpe= 0.11 min. 
\jpe=0.ll mm. 
Zooecia 
L, s=0.35 mm. 
?.3=0.25 mm. 
Affinities . — Only the two specimens figured have been found, and we, therefore, 
have not been able to make a detailed study of the species. 
This species differs from Tessaradoma ornata in its spiramen which is median 
and close to the peristomice and in its wide peristome which may attain 0.15 mm. 
in diameter. 
Occurrence . — Upper Jacksonian (Ocala limestone) : West bank Sepulga River. 
Escambia County, Alabama (rare). 
Cotypes.— Cat, No. 64171. U.S.N.M. 
Genus TREMOTOICHOS Canu and Bassler, 1917. 
1917. Tremotoichos Canu and Bassler, Synopsis of American Early Tertiary Cheilostome 
Bryozoa, Bulletin 96, United States National Museum, p. 59. 
The frontal and the dorsal are tremocysts with sulci. The spiramen opens 
interiorly at the level of the operculum; exteriorly it is distant from the peristomice 
and almost never placed on the median axis of the zooecia. 
Genotype. — Tremotoichos rectifurcatum Canu and Bassler, 1917. 
Range . — J acksonian. 
This genus possesses all the characters of Semihaswellia , the difference being 
little perceptible and consisting solely in the place of the spiramen. As the latter 
does not appear to exercise the same physiological function (according to Jullien) 
as in Semihasw ellia. we believe it necessary to create a new genus. 
TREMOTOICHOS RECTIFURCATUM Canu and Bassler, 1917. 
Plate 67, figs. 4-23. 
1917. Tremotoichos rectifurcatum Canu and Bassler, Synopsis of American Early Tertiary 
Clieilostome Bryozoa, Bulletin 96, United States National Museum, p. 59, pi. 6, fig. 1. 
Description . — The zoarium is free, subcylindrical, branched almost at a right 
angle. The dorsal is very thick; deprived of avicularia and formed of a tremocyst 
with tubules and with sulci. The zooecia are indistinct; the frontal is a tremocyst 
with sulci placed on an olocyst with very small perforations. The peristome is 
salient, perpendicular to the zoarial plane, thick, and provided with a small proxi- 
mal avicularium ; the peristomice is orbicular. The spiramen is a pore of the 
frontal placed on the right or left of the median axis and distant from the peri- 
stomice. 
Measurements- 
. , . rA»e=0.10mm. 
-i eristomice . 7 „ , „ 
Hpe= 0.10 mm. 
Zooecia. — Lz= 0.70 mm. 
Variations . — The spiramen is not always apparent (fig. 7) ; it is confused with 
the tremopores. The peristome of the young zooecia (fig. 5) is thin. The sulci 
