258 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
EURITINA TECTA, new species. 
Plate 5, figs. 1-7. 
Description . — The zoarium is free and bilamellate. The zooecia are distinct, 
very elongate, vaguely oval; the mural rim is thin, thickened laterally, and forms 
the two lateral facets of the cryptocyst. The cryptocyst is smooth, flat, oblique 
toward the opesium. The opesium is elongate entire, elliptical, or it may have a 
proximal border more or less straight. The ovicell is hyperstomial, never closed by 
the opercular valve, globular, salient, smooth. The primoserial 
zooecia have special avicularia without pivot, marked with a distal 
convexity protruding much above the zooecial plane. 
, r\ ■ f A<9=0.22 mm. 
Measurements . — Opesia < 1 _ n 
Zooecia 
lfo=0.12 mm. 
Zs=0.45-0.50 mm. 
lz= 0.25 mm. 
Fig. 69.- — Genus 
Labiopora Lev- 
insen, 1909. 
Labiopora crcn- 
ulata Levinsen, 
1909. Zooecia, X 
23 (After Levin- 
sen, 1909). 
Variations . — The lateral grooves are very constant on the 
bilamellar zoaria, but on specimens which contain supple- 
mentary lamellae, the zooecia are devoid of them and appear 
to belong to another species (fig. 1). The cryptocyst and 
the mural rim are formed of very large but very compact 
olocystal elements (fig. 3). They are a little oriented on the 
mural rim according to the general rule. The cryptocyst is 
often divided into two symmetrical parts by a longitudinal 
linear junction (fig. 3). The bottom of the zooecia is the 
ordinary olocyst (fig. 4). The interior of the zooecia (figs. 
5, 6, 7) does not correspond at all to the exterior. There is no 
trace of the grooves in the cryptocyst, and the lower opesial border is much thick- 
ened as in Aspidostoma Hincks, 1881. 
The primoserial zooecia- quite different in form at the surface, have in the 
interior a shape exactly identical with the other zooecia, although plainly nar- 
rower. The exterior distal convexity of these zooecia is very constant and reminds 
one somewhat of a little roof. Figure 2 shows a regenerated zooecium of quite 
unusual character. Here a normal zooecium succeeds a “calcified” one. 
O ecu rrence . — Mi d w ay a n (Clayton limestone) : One mile west of Fort Gaines, 
Georgia (common) ; Mabelvale, near Little Rock, Arkansas (common). 
Cotypes. — Cat. No. 63807, U.S.N.M. 
Genus LABIOPORA Levinsen, 1909. 
1909. Labiopora Levinsen, Morphological and systematic studies on the Cheilostomatous 
Bryozoa, p. 171. 
No ovicell; distinct raised margins; frontal wall of polypide-tube not quad- 
rangular and not surrounded by projecting flanges. Polypide-tube bilabiate, on 
