NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
469 
opens largely into the peristomie. 
pivot. 
iij . td - , \hpe= 0.1 0 mm 
Measurements .- — Peristomice 
The median avicularium is elliptical, without 
„ . fZs=0.55-0.60 mm. 
Ipe— 0.10 mm. moeci a j j 3= q ^ mm . 
Affinities . — The areolae disappear very easily through alteration in fossiliza- 
tion. Their absence on the fossils is therefore not a proof of a difference in struc- 
ture. We do not hesitate to classify this species in Smittina , for the frontal is decep- 
tive in this genus. Moreover the few specimens figured are the only ones found. 
It is probable that when better ones are discovered they 
will be found provided with areolae as usual in the 
genus. 
Occurrence. — Vicksburgian (Marianna lime- 
stone) : West Bank Conecuh River, Escambia County, 
Alabama (very rare) ; well in Escambia County, Ala- 
bama (very rare). 
Cotypes. — Cat. No. 64297, U.S.N.M. 
SMITTINA ORBAVICULARIA. new species. 
Plate 61, tigs. 1—4. 
Description . — The zoarium is unilamellar and 
creeps over algae. The zooecia are large, elongated, 
distinct, wide, claviform or turbinate. The frontal is 
little convex, surrounded by large crowded areolae and 
short interareolar costules. The peristome is thick and 
little salient; the peristomice is orbicular; the apertura 
(in the interior) is semilunar, transverse with a straight 
or somewhat concave proximal border; the lyrula is 
visible only in the interior; it is short and rectangular. 
The ovicell is small, little salient; it is formed of a very 
fragile area surrounded by a collar which is little visi- 
ble; the ovicell is hyperstomial and opens into the peri- 
stomie. The avicularium is orbicular , with pivot; it is 
large, placed eccentrically with at least two orifices for 
which raise the semicircular mandible. 
Fig. 132w. — Genus Smittina 
Norman, 1903. 
A, B. Smittina okaroensis 
Levinsen, 1909. A. Several 
zooecia, X 55, showing vibra- 
cula provided with trabecular 
pivot. B. Operculum, X 100, 
with form different from the 
ordinary. (After Levinsen, 
1909.) 
the passage of the muscles 
Apertura j ha=0.10 mm. 
(interior) | Za=0.15mm. 
Measurements . — Peristomice r hpe—Q.Yl mm. 
(exterior) ! lpe= 0.12 mm. 
ry . f £.3=0.90-1. 00 mm 
[Z.s= 0.40-0. 50 mm. 
Affinities . — The avicularium of this species 
okaroensis Levinsen, 1909 (fig. 132?;), dredged off New Zealand, 
which is separated from the zooecium by a broad, arched line, is provided at the 
margin with 3-5 pores, and the transverse bar (pivot) which divides the frontal 
resembles that 
of Smittina 
Its chamber 
