NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 201 



Family THEONOIDAE Busk, 1859. 



Genus THEONOA Lamouroux, 1821. 



THEONOA GLOMERATA Ulrich and Sassier, 1904. 



Plate 26, figs. 9-12. 

 1904. Theonoa glomerata Ulrich and B.^ssleh, Maryland Geological Survey, Miocene, p. 406. 

 pi. 109, figs. 4, 5. 



The original description of this species was as follows: 



Zoarium cake shaped when young and grow-ing irregular w-ilh age, the under side covered with a 

 concentrically wrinkled epitheca, the upper side with short or broken irregularly arranged celluIiferouB 

 ridges separated by deep interspaces. Ridges abruptly elevated, their flattened summits usually 

 exhibiting a double row of subangular zooecial apertures. Here and there, probably through confluence 

 of two or more ridges, considerable clusters of apertures occur, while other groups may not contain 

 more than three or four cells. Occasionally an irregular radial arrangement of the ridges is apparent. 

 About four zooecial apertures in 1.0 mm. 



Occurrence. — Miocene (St. Mary's formation) ; St. Marys River, Maryland (rare) . 

 Cotypes.—C&t. No. 68746, U.S.N.M. 



Family DIAPEROECIIDAE Canu, 1918. 



Genus STATHMEPORA Canu and Bassler, 1922. 



Greek: stathme = line or cord. In allusion to the rectilinear form of the 



fascicles. 



The ovicell is a vesicle traversed by the tubes of which the peristomes are 

 much scattered. The tubes are cylindrical and grouped in linear, uniserial fascicles. 

 Gemmation is triparietal. 



Genotype. — Stathmepora flahellata, new species. Pleistocene. 



STATHMEPORA FLABELLATA, new species. 

 Plate 43, figs. 10-17. 

 Description. — The zoarium is bushy and formed of bilamellar, fiabellate fronds. 

 The fascicles are imiserial, little salient, arranged perpendicularly to the zoarial 

 margins. The tubes are visible only when they are isolated. The ovicell is an 

 irregular vesicle pierced by fascicles whose tubes are then more adjacent. 

 Measurements. — 



Diameter of the peristome 0. 12 mm. 



Zooecial diameter — 0-18 mm. 



Distance between the peristomes 1-00 mm. 



Separation of the peristomes 0. 56-0. 80 mm. 



Variations.— The fascicles are not exactly analogous to each other. They 

 form, moreover, some lines with tubes adjacent like true fascicles. The basal 

 lamella is large and the zone of growth is thick. 



The ovicell is formed after the consolidation of the adjacent tubes, for the 

 fascicles are not disarranged. If the peristomes are scattered the peristomies are 

 long and never adjacent. It is probable that fossilizatiou caused the long non- 

 adjacent peristomies to disappear from the species, of which the bases alone are 



visible. 



12184— 23— Bull. 125 14 



