598 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Genus SCHISMOPORA MacGillivray, 1888. 
1888. Schismopora MacGillivray, Bryozoa in McCoy’s Prodromus of the Zoology of Vic- 
toria, vol. 2, dec. 17, p. 253. 
The ovicell is perforated. The frontal is smooth. The apertura bears a 
proximal rimule. No spines. 15-20 tentacles. 
Genotypes. — Schismopora ( Gellepora ) coronopus S. Wood, 1850, and Sckis- 
mopora (Gellepora) pumicosa Busk, 1851. 
Range. — J acksonian — Recent. 
Historical. — This is the Pumicosa group of Waters, for which he has always 
preserved the name of Gellepora until 1913, when certainly it was by error that he 
called it Osthimosia. The latter genus of Jullien is perfectly limited as he described 
it in 1901 and 1909. The genus Schismopora MacGillivray, 1888, has a much more 
general meaning, since he applied it to all the Cellepores with proximal rimule. 
We preserve it, however, with a more restricted meaning so as not to create a new 
name. 
Certain recent species classified in this genus are provided with tremopores; 
it will be necessary to create a special genus for them. 
SCHISMOPORA GLOBOSA, new species. 
Plate 75, figs. 7-15. 
Description. — The zoarium is massive, globular , measuring as much as 18 milli- 
meters in diameter. The superficial zooecia are distinct, little erect, irregularly 
ovoid; the frontal is smooth and convex and bears an avicularium as large as the 
apertura. The apertura is oval and garnished with a wide triangular rimule. The 
deep zooecia are visible only through their apertura. The incomplete zooecia are 
rare. No interzooecial avicularium. 
M easurements. — Apertura 
rAa=0.15 mm. 
I7a=0.10 mm. 
Variations. — The frontal avicularium is almost always broken; it leaves a wide 
cicatrix of little. depth (fig. 11). 
The transversal section (fig. 13) perfectly oriented is very instructive; it is 
the perfect type of the Celleporid accumulation. Above each zooecium there is 
a small triangular chamber which appears to correspond to the frontal avicularium; 
the plates of these small chambers unite two by two, outlining the zooecial contours. 
The skeletal tissue is an olocyst whose elements are scattered or piled together 
(fig. 14). 
Affinities. — In its large zoarium and its frontal avicularium this species much 
resembles Iloloporella glomerata Gabb and Horn, 1862. It differs from it in the 
different form of its apertura, in the absence of areolae, and its very little elevated 
zooecia. 
Occurrence. — Lower Jacksonian (Moodys marl) : Jackson, Mississippi (com- 
mon). 
Gotypes. — Cat. No. 64213, U.S.N.M. 
