340 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



SCHIZOPODRELLA LINEA Lonsdale, 1845. 



Plate 45, figs. 10-18. 



1845. Eschara linea LONSDAI.E, Account of twenty-six species of Polyparia obtained from 

 the Eocene Tertiary formation of North America, Quarterly Journal Geological 

 Society London, vol. 1, p. 530, fig. 



1862. Escharinella f linea GABB and HORN, Monograph of the fossil Polyzoa of the Sec- 

 ondary and Tertiary formations of North America. Journal of the Academy of 

 Natural Sciences of Philadelphia, ser. 2, vol. 5, p. 140. 



Description. The zoarium is free, bilamellar; the two lamellae are insepar- 

 able. The zooecia are large, elongated, distinct, elliptical; the frontal is convex 

 and formed by a thick tremocyst closely united with a very thin inner olocyst, 

 the interior of which is very finely perforated. The aperture is semilunar; the 

 proximal border is a little concave and bears a narrow rimule. The hyperstomial 

 ovicell is salient, globular and smooth. Two small avicularia are symmetrically 

 disposed on each border of the aperture; they have a fragile pivot; the beak is 

 directed toward the median zooecial axis. 



,, |7i<7=0.15mm. (including rimule). 



Measurements. Aperture { , 



l/ff=0.12mm. 



( Z3=0.75-0.90 mm. 



. 

 Zooecia< -, . r ~ - 



[lz 0.45-0. 65 mm. 



Variations. There are some zooecia which are narrow (fig. 12), some wide 

 (fig. 13), and others very irregular. Often the zooecia are surrounded by a 

 prominent thread (fig. 14). The ovicell is always smooth. This is a peculiarity 

 which is very rare in the bryozoa, as the ovicell and the frontal are generally of 

 the same nattu-e. The small oral avicularia are very constant; sometimes there 

 is one of them which is abortive (figs. 13, 14) ; the pivot (fig. 14) is very fragile 

 and often missing on the fossils. 



The interior is furnished with a thin perforated olocyst (fig. 17). Upon 

 rubbing away the interior it may be noted that the tremopores are bound together 

 by a system of small canals radiating from the median axis of the zooecia. Their 

 intersection with the calcareous deposit over the tremopores form reticulations 

 visible in tangential sections (fig. 16). The tremopores are funnel shaped and are 

 much larger on the exterior than on the interior. 



On account of the size of its fronds this is an easily recognized bryozoan. 



Affinities. This species is very close to ScMzopodrella unicornis Johnston, 

 1847, but differs in its smaller, less prominent avicularia, which are turned toward 

 the interior of the aperture and not toward the exterior of the zooecia. 



It differs from Schisopodrella viminea Lonsdale, 1845, in its wider zooecia, 

 and its two symmetrical avicularia. 



It differs from Schisopodrella marginata in its micrometric dimensions which 

 are twice as large, and in the presence of the two oral avicularia. 



Occurrence. Middle Jacksonian : Type-locality, Eutaw Springs. South Caro- 

 lina (very common) ; near Lenuds Ferry, South Carolina (abundant) ; Wilming- 

 ton, North Carolina (rare). 



Plesiotypes.Czt. No. 64052, U.S.N.M. 



