XOKTII A.MI.KICAX KAULY TERTIARY BRYOZOA. 125 



PERIPOROSKLLA TANTILLA Canu and Bassler, 1917. 



Plato '24. tigs. 7-12. 



1917. Periporoaella tuntilln <IAXI- and HASSI.F.K, .Synopsis American Early Tertiary Cheilo- 

 stonio Bryozoa, Bulletin '.Ml. United States National Museum, ]>. 1!>, ]il. -, tis. 3. 4. 



The zoarium is free, formed by two lamellae joined together and inseparable. 

 The zooecia are generally indistinct, very elongated, rectangular; the mural rim is 

 broad, flat, enlarged at. the base. The opesium is elliptical, somewhat enlarged 

 listally, and very linely denticulated. The ovicell is deep but placed above the 

 large distal septula; it projects but little exteriorly. The avicularia are inter- 

 zooecial, rare, elliptical, without pivot, but with two lateral denticles; numerous 

 dietellae in each zooecium. 



c 



,, . fA0=0.30-0.40 mm. 



.u< iixiircinents. Opesia , Zooecia 



/^ n 1 1 _u 10. n ltll 



lZo=0.11-0.19 mm. 



Zs=0.40-0.50 mm. 



?s=0.25 mm. 



T conations. In this species we have one of the most peculiar types of Mem- 

 branipores. The dietellae arranged entirely around each zooecium (figs. 10, 11) 

 are covered by an epithecal olocyst analogous to the olocyst of the mural rims in 

 the Membranipores. These elements group themselves in a radial manner about 

 the opesium (fig. 1-2). 



Another interesting peculiarity is the mode of gemmation of the zooecia which 

 are arranged in parallel linear series, and every new row appears invariably on one 

 of the free edges of the zoarium. 



The large distal septula opens in a dietella, which establishes communication 

 with the succeeding zooecium. and its opening is often visible in the latter. 



This type of structure is different from all others on account of its dietellae, its 

 method of gemmation, its ovicell. and even its avicularia. It certainly belongs to a 

 family which our present zoological knowledge will not yet permit us to suspect. 



Occurrence. Middle Jacksonian : Wilmington, Xorth Carolina (common); 

 near Lenuds Ferry, South Carolina (rare) ; Eutaw Springs. South Carolina (rare). 



Cotypes. Cat. Xo. 62577. U.S.X.M. 



Genus ELLISINA Norman, 1903. 



1903. EUisina NORMAN, Natural History of East Flnmark, Annals and Magazine Natural 

 History, ser. 7. vol. 11. p. 50(3. 



The zooecia are furnished with avicularia, ovoid or triangular, situated on the 

 hinder portion of the zooecium. The ovicell is well developed, typically with a 

 flattened area on its fi-ont. In (he type-species the pore-chambers (dietellae) are 

 very large; one distal; the position of the remaining chambers is very unusual, 

 the two front lateral pairs project outside the side walls; and the two posterior 

 pairs are seen inside the side walls which is the reverse of the usual rule. 

 ( Xorman ) . 



3ff'iiil'<iii'//>(,,',i levata Ilincks, 1SS2. 

 c. Senonian-Eecent. 



