548 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
It differs from Tubucella gibbosci in the absence of large zoarial gibbosities 
around certain peristomies. 
On account of the size of the fragments this is an easily recognized fossil. 
Occurrence. — Middle Jacksonian: Wilmington, North Carolina (common): 
Eutaw Springs, South Carolina (very rare), 
Cotypes. — Cat. No. 62605, U.S.N.M. 
TUBUCELLA GIBBOSA, new species. 
Plate 71, figs. 1-9. 
Description . — The zoarium is 'free, bilamellar, dichotomously branched; the 
fronds are wide and compressed. The zooecia are indistinct; the peristomiale is 
Fig. 161. — Genus Tubiporella Levinsen, 1909. 
A-D. Tubiporella magnirostris MacGillivray, 1882. A. Group of zooecia showing two peri- 
stomial ovicells, X 23. B. View after removal of the basal surface. Two ovicells are seen and 
the three zooecia show a distinct vestibular arch, X 23. C. A part of the surface of a zooecium, 
X 55. D. A sagittal section through the. zoarium. An ovicell is seen proximally and the two 
zooecia show a vestibular arch at the beginning of the peristomial tube, X 17. (A-D after 
Levinsen, 1909.) 
a little smaller than the frontal and they are separated from each other by a 
small ascopore; the pores of the frontal are a little smaller than those of the peri- 
stomiale. The peristomie is salient, little thickened; the peristomie is very long 
and arched. Around the peristomie of certain zooecia the tubules are much de- 
veloped, forming on the zoarium very prominent gibbosities. 
,, , „ (Peristome— 0.20 mm. 
Measurements . — Zooecia T „ 
12/0=0.85 mm. 
Affinities .- — The gibbosities which characterize this species are quite original. 
The sections which we have prepared (figs. 8, 9) show that they result from the 
extraordinary development of the tubules around certain peristomies. The zooecia 
which bear them are without ovicells. In Tubucellaria nodosa it is, on the con- 
