NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
77 
Genotype. — Electra pilosa Linnaeus, 1758. Range. — Eocene-Recent. 
The recent species belonging to this genus are according to Levinsen and 
Waters : 
Electra ( Flustra ) pilosa Linnaeus, 1758. 
Electra verticellata Lamouroux, 1816. 
Electro. ( Membranipora ) bellula , Hincks, 1880. 
Electra ( Flustra ) triacantha Lamouroux, 1816. 
Electra ( Membranipora ) distorta Hincks, 1880. 
Electra ( Tendra ) zosteri cola N or dm an. 1839. 
Electra ( Membranipora ) monostachys Busk, 1852. 
Electra ( Membranipora ) bicolor Hincks, 1880. 
Electra ( Membranipora ) tenclla Hincks, 1880. 
ELECTRA PARVIMATER, new species. 
Plate 19, figs. 1-3. 
1 description .- — The zoarium incrusts oysters; it is uniserial around the ances- 
trula, but later it develops into multiserial branches. The zooecia are elongated, 
distinct, pyriform ; the gymnocyst is smooth and convex; the mural rim is enlarged 
at the base, flat, and finely striated. The opesium is large, oval, very finely crenu- 
lated. The ancestrula is very small. 
Measurements. — Opesium mm " Zooeciumj^" nim * 
r [ to =0.1 6 mm. \lz— 0.24 mm. 
Affinities . — This species belongs to the group of Electra monostachys Busk, 
1852. It differs from Busk’s species in its smaller micrometric dimensions and in 
the oval form of the zooecia. Moreover the extreme smallness of the ancestrular 
zooecia has not been noted in this latter species. 
Occurrence . — Lower Jacksonian (Moodys marl) : 21 miles north of Robert, 
Newton County, Mississippi (rare). 
Holotype. — Cat. No. 65865, U.S.N.M. 
Genus MEMBRANIPORA Blainville, 1834. 
1834, Membranipora Blainville, Manuel d’Actinologie ou de Zoophytologie, p. 447. 
No gymnocyst on the frontal. Two spines at least. 
Genotype. — Membranipora mcmbranacea Linnaeus, 1758. Miocene-Recent. 
The living species belonging to this genus are, according to Waters: 
M embranipora mcmbranacea Linnaeus, 1758. 
M embranipora danica Levinsen, 1894. 
Membranipora ( Flustra ) tuberculata Bose, 1802. 
M embranipora ( Flustra ) inca D’Orbigny, 1839. 
1 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 vibraculum, Lon and Ion for the onyeho- 
cellaria, ha and la for the apertura, etc. 
