THE 
GHOLOGICAL MAGAZI 
NEW SERIES. DECADE VI. VOL. Afiansonian Insti; > 
allen Le S v. 
No. VI.—JUNE, 1916. JUN 17 1916 
ORIGINAL ARTICLES. 
Ws 
' Tea “Honal Musew™ 
I.—NoreEs oN NEW OR IMPERFECTLY KNOWN CHALK Potyzoa. 
By R. M. Bryvons, F.G.S. 
(Continued from the March Number, p. 100.) 
PLATE X. 
MEMBRANIPORA MISSILIS, sp. nov. (PI. X, Figs. 1, 2.) 
Zoarium unilaminate, adherent. 
Zoecia strongly pyriporiform, very small, length about -4 mm.; 
areas broadly speaking elliptical but with a strong tendency to have 
the upper end flattened rather askew to the central line, average length 
"18mm., breadth -11mm.; the side walls of the area bear about 
a dozen tubercles so small that their existence is only just recognizable 
under a 38 in. objective; a 1 in. objective shows them to be 
perforated ; below the area there is typically (after the early stages) 
a small perforated boss placed centrally on the front wall, but when 
the front wall has to accommodate an ocecium the boss splits into two, 
often very massive, one on either side of the ocecium. 
Owcia very large in proportion, globular but tending to end in 
a definite but blunt point like an artillery shell; free edge narrowly 
and deeply concave. : 
_ Avicularia vicarious, fairly numerous, consisting of a shallow and 
wide pan with a small rounded aperture at the lower end; over the 
lower part of this aperture the side walls are sharply pinched in. 
This species appears in the zone of Marsupites in Hants and Sussex, 
where it is rare, and also occurs very sparingly in the zones of 
Offaster pilula and <Actinocamax quadratus. It has a superficial 
resemblance to J. coralliformis, Bryd.,} which is curiously strong 
considering that their avicularia are the only point of resemblance 
in detail. z 
Memeranipora Fanwia,? sp. noy. (Pl. X, Figs. 3, 4.) 
Zoarium unilaminate, adherent. 
Zoeeia pyriporiform, of fair size, length about -5 mm.; areas 
corresponding in shape to those of IL misslis (supra), average length 
‘29mm., breadth -2 mm., surrounded by a flat rim which is narrow 
1 GEOL. MaG., 1910, p. 259, Pl. XXI, Figs. 4, 5. 
2 The difficulty of finding any Latin word at once distinctive and appropriate 
as a specific name in a genus such as Membranipora, with its hundreds of 
species already described, is so acute that I have followed the example set by 
D’Orbigny with Hschara of using classical names. He got as far as H, so 
I have begun with F. 
DECADE VI.—VOL. III.—NO. VI. 16 
