NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 
19 
Genus PYRIPORA D’Orbigny, 1852. 
(For description see Bulletin 106, U. S. National Museum, p. 78.) 
PYRIPORA BREVICAUDA, new species. 
Plate 9, figs. 2-4. 
Description. —The zoarium encrusts Cellepore bryozoa. The zooecia are pyri¬ 
form, little narrowed behind, elongated, distinct, separated by a furrow; the gym- 
nocyst is convex and very short. The opesium is elliptical or oval, anterior. 
Measurements . 3 —Opesia' 
7m = 0.20 mm. 
lo — 0.12 mm. 
Zooecia 
£2 = 0.40 mm. 
Iz =0.22 mm. 
Variations.—' This small species is of a disconcerting irregularity, especially 
since the substratum itself is very irregular. The calcified zooecia bear a large 
elliptical pore. The heterozooecia are numerous and generally fusiform. The 
zoarial expansions appear to be flabelliform. 
Occurrence. —Miocene: Kuhns, Carteret County, North Carolina (rare). 
Cotypes. —Cat. No. 68399, U.S.N.M. 
Genus MYSTRIOPORA Lang, 1915. 
1915. Mystriopora Lang, New Uniserial Cretaceous Cheilostome Polyzoa, Geological Magazine 
ser. 6, vol. 2, p. 502. 
MYSTRIOPORA (?) AREOLATA, new species. 
Plate 33, figs. 1, 2. 
Description. —The zoarium is incrusting. The zooecia are distinct, separated 
by a deep furrow, elongated, pyriform; the gymnocyst is short, convex, smooth, 
much narrowed. The mural rim is thin, garnished all around with hollow spines; 
the opesium is large, oval, anterior; between the zooecia. are some zooeciules whose 
opesium is also garnished with some spines. The zooecia are separated from each 
other by rectangular areolar spaces. Dietellae are present. 
fk = 0.45 mm. „ . \Lz = 0.60 mm. 
Measurements . 3 —Opesia-!'"" 'Cl't Zooecia-L _ _ n 
r Uo =0.25 mm. 1/2 =0.50 mm. 
Affinities.— The Cretaceous genus Mystriopora Lang, 1915, shows also zoo¬ 
eciules (although the English authors thought them to be more in the nature of 
avicularia) and areal spines, but it did not have areolar spaces between the zooecia. 
Our specimens appear, therefore, to belong to a new genus, although we prefer to 
employ Lang’s name provisionally because the rarity of specimens has not per¬ 
mitted us to make a tangential section in order to discover the dietellae and to 
establish the nature of the areolar spaces. We have observed cases of double and 
triple regeneration of the polypide. 
This species differs from Membranipora pedunculata Hincks, 1881, also pro¬ 
vided with zooeciules, by the absence of spines and by the presence of areolar spaces. 
Occurrence. —Pleistocene: Santa Monica (Long Wharf Canyon), California 
(rare). 
Cotypes. —Cat. No. 68400, U.S.N.M. 
8 In the citation of measurements ho is the length and lo the width of the opesia, Lz and Iz similarly the length and width of 
the zooecia, Lv and Iv the same for the vibraculum, Lon and Ion for the onychocellaria, ha and la for the apertura, etc. 
