166 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
incompletely calcified ectooecinm. which is again surrounded by avicularia. 
(Levinsen.) 
Genotype. — Tegella { M embranipora ) unicornis Fleming, 1828. 
Range. — Santonian-Recent. 
The recent species of the genus are : 
Tegella ( Membranipora ) unicornis Fleming, 1828. 
Tegella { Membranipora ) sophiae Busk, 1885. 
Tegella {Membranipora) occultata Robertson, 1908. 
Fig. 40. — Genus Tegella Levinsen, 1909. 
A-I. Tegella unicornis Fleming, 1828. A. Ovicelled zooecia, X 50. (After Hincks, 1880.) 
B, C. Two views, X 40, showing development of the avicularium. (After Levinsen, 1909.) 
D. Zooecia, X 20. E. Distal wall with uniporous septulae, X 40. F. Lateral wall, showing 
multiporous septulae, X 26; av, avicularium; oc, ooecium. G. Section through the ovicell, X 83; 
av, avicularium; f, f. septulae. H. Inferior face, X 16. I. A multiporous septula, greatly 
magnified. (D-I after Levinsen, 1894.) 
The fossil species are; 
Tegella {Membranipora) grifftthi Brvdone, 1906. 
Tegella {Membranipora) triminghamensis Brydone, 1910. 
In reality in the fossil species the avicularium does not surround the ovicell, 
but surmounts it and is intimately attached to it. 
TEGELLA ACULEATA, new species. 
Plate 30, fig. 11. 
The zoarium incrusts small shells. The zooecia are large, distinct, elongated, 
pyriform, with a long convex gymnocyst; the mural rim is salient, very thin, 
regular, with 4 to 8 distal hollow spines. The opesium is anterior, oval, or elliptical, 
