NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
311 
M easurements . — < 
( Tz— 0.50-0.60 mm. 
1/3=0.25-0.35 mm. 
Affinities . — The discovery of a member of the Cribrilinidae provided with an 
endozooecial ovicell is very important, as it indicates clearly that the structure of 
the frontal has no connection with the various organs (ovarian) of the polypide. 
At the same time the presence of the costules does not imply the muscular system 
of the Anasca, since the form of the aperture indicates a characteristic compen- 
satrix of the Ascophora ; this frontal has no connection with the hydrostatic system. 
The costular structure has no special function, being only a decoration or, 
to be exact, an adaption for a particular purpose, and it can not be employed to 
characterize a natural family. 
This species must not be confounded with any species of the genus Figularia 
Jullien, which is provided with a hyperstomial ovicell. 
Occurrence . — Middle Jacksonian (Castle Hayne limestone) : Wilmington, North 
Carolina (rare). 
Bibliography ( Anatomical ). — 1881. Hincks, Contribution toward a general History of the 
Marine Polyzoa, Annals Magazine Natural History, ser. 5, vol. 8, p. 57, pi. 3, fig. 6.— 1884. Hincks ? 
Contribution toward a general History of Marine Polyzoa, Annals Magazine Natural History, 
ser. 5, vol. 4, p. 129, pi. 8, fig. 5. — 1884. Busk, Report on the Scientific Results of the Voyage 
of the Challenger, pt. 1, Cheilostomata, vol. 10, pt. 30, p. 133, pi. 19, fig. 8. — 1887. Waters, 
Bryozoa from New South Wales, North Australia, Annals Magazine Natural History, ser. 5, 
vol. 20, p. 187, pi. 6, fig. 7. — 1888. Julijen, Mission scientific du Cap Horn, vol. 6, Zoology, 
Bryozoaires, p. 63, pi. 3, figs. 8, 9. — 1906. Waters, Bryozoa from Chatham Island, Annals 
Magazine Natural History, ser. 7, vol. 17, p. 16, pi. 1, fig. 11. 
The cribriform area is formed by the coalescence of hollow branched spines 
attached to the lateral walls. The lacunae are concentrically arranged and semi- 
lunate with an interior denticule. The opercular valve is membranous. The ovicell 
is hyperstomial and opens into a small peristomie above the operculum ; it is closed 
by a special operculum and is formed by a double calcareous deposit. The lateral 
walls have septular disks with 1 to 3 pores; the distal walls bear only septules; 17 
tentacles. 
Genotype. — Arachnopusia ( Lepralia ) monoceros Busk, 1854. 
Range. — Vicksburgian-Recent. 
Description . — The zoarium incrusts shells. The zooecia are distinct, separated 
by a furrow, at the bottom of which there are some small, elliptical, wide pores; 
Ilolotype. — Cat. No. 62588, U.S.N.M. 
Genus ARACHNOPUSIA Jullien, 1886. 
ARACHNOPUSIA VICKSBURGICA, new species. 
Plate 85, figs. 1-3. 
