268 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
opercular valve; the polypide tube is continued, proximal iy beneath the crvptocyst 
cover. (After Levinsen, 1909.) 
Genotype. — Siphonoporella ( M ernbranipora ) delicatissima Busk, 1861. 
Family THALAMOPORELLIDAE Levinsen, 1909. 
The tubifer zooecia have calcareous spicula in the shape of compasses and 
bows. The ovicells are hyperstomial, with two calcareous layers, springing from 
the whole anter of the apertura ; 
they are closed by a horizontal 
cup-shaped chitinized operculum 
which is connected at its base, 
with the operculum of the gono- 
zooecium. The opesiulae are ah 
ways completely separated from 
the apertura. The opercular 
valve is membranous or chitin- 
ized, and more or less completely 
separated from the ectocyst by a 
single or double chitinous scle- 
rite. Interzooecial avicularia 
occur. 
The principal characters of 
this family are shown in figure 
73. Hitherto it has been consid- 
ered as appearing first in the 
A-E. Thalamoporella rozieri Audouin, 1826. A. View of Miocene. The only specimens 
the typical form, X 25. (After Waters, 1908.) B. Zooecia, which we have found OCCUr in 
X 20, o± var. vrommens Levinsen, 1909. C. Zooecia, X 20, . . , -. . ,, T7 . 
of var. californica Levinsen, 1909. D. Zooecia, X 20, of var. ^ ie topmost iec s O - ie 1C S 
sparsipunctata Levinsen, 1909. E. Zooecia, X 20, of var. burgian. 
labiata Levinsen, 1909. (B-E after Levinsen, 1909.) The known genera are Thala- 
moporella Hincks, 1887 ; Thairo- 
pora MacGillivray, 1887, Manzonella Jullien, 1888, and W oodipora Jullien, 1888. 
Genus THALAMOPORELLA Hincks, 1887. 
1SS7. Thalamoporella Hincks, Critical Notes on Polyzoa, Annals Magazine Natural History, 
ser. 5, vol. 19, p. 164. 
Characters same as for the family. 17-19 tentacles. 
Genotype. — Thalamoporella ( Flustra ) rozieri (Savigny) Audouin (1812) 
1826. 
Range. — Aquitanian — Recent. 
Fossil species of this genus: Thalamoporella ( Eschara ) andegavensis Michelin, 
1846. 
