BRYOZOA. (331 



PI. 66, is faulty in having the cell apertures too small, and in 

 not showing- any accessory pores. The latter were first detected 

 after the plates had been printed. 



The isolation of the branches and consequent resemblance to 

 Pmnntopom. distinguish this species from S. subquadrans. The 

 zooecia are also slightly larger. Fragments of similar appear- 

 ance, but apparently belonging to a distinct species, have been 

 noticed. One of them is represented by fig. 9a, on PI. 66. This 

 agrees very closely in its minute features with S. subquadrans, 

 and may represent a variety of that species. 



Position and locality: Chester group, Sloan's Valley, Ky. 



SEPTOPORA BISERIALIS Swallow. 



PI. LVI, fig. 11. 



Synocladia rirgulacea? Swallow. 1858. Trans. St. Louis Acad. Sci. vol. 1, p. 179. 



Syttocladia biserialis Swallow, 1858. Trans. St. Louis Acad. Sci. vol. 1, p. 179. 



Synocladia biseriaUs Meek, 1872. Pal. E. Neb. p. 156, pi. 7, flg. 5a-5e. 



>ynocladia biserialis Meek, 1874. Am. Jour. Sci. and Arts. p. 486. 



Synocladia biserialis Meek, 1875. Pal. Ohio, vol. 2, p. 326, PI. 20, flg. 5-5b. 



Synocladia biserialis White, 1877. Wheeler U. S. Geol. Surv. vol. 4, p. 107, PI. 7, flg. 3a-3c. 



Zoarium large, irregular, infundibuliform, strongly folded and 

 often overlapping in the upper portions, consisting of approxi- 

 mately equal, parallel radiating branches, their number increas- 

 ing by lateral divisions, or intercalation of new branches, the 

 whole being united into a fenestrated frond by the union of the 

 lateral branchlets or pinna?, which form more or less arched 

 dissepiments. Fenestrules usually transversely oblong, often 

 irregularly quadrangular or somewhat crescentic, wider than 

 the branches, about thirteen in 1 cm. Branches averaging 0.5 

 mm. wide, but varying from 0.3 or 0.4 to 0.7 or 0.8 mm., with 

 nearly uniformly ten in 1 cm.; reverse evenly rounded, with fine 

 minutely granulose striae, and a variable though never large 

 number of accessory pores, chiefly occurring on the sides of the 

 branches; their mouths are circular, about 0.07 mm. in diame- 

 ter, and, when perfect, with a slightly elevated rim. The dis- 

 sepiments are about two-thirds as wide as the branches, and. 

 on the reverse side, more or less depressed below them, and 

 striated. On the obverse face the branches and dissepiments 



