326 PALAEONTOLOGY OF OHIO. 



COAL-MEASURE SPECIES. 



MOLLUSCA 



POLYZOA. 



Genus SYl!fOCLADlA, King, 1849. 



(Ann. Mag. N. H., 2d ser., III., 388.) 



Synocladia bisekialis, Swallow. 



Plate 20, figs. 5a, 6. 



Synocladia biserialis, Swallow (1858), Trans. St. Louis Acad. Sci., I., 179; Meek (1872), 

 Palseont. Eastern Nebraska, in Hayden's Report, U. S. Geol. Survey of Nebraska, 

 156, pi. VII., figs. 5a-e ; also (1874) Am. Jour. Sci. and Arts, 486. 



Compare Sepiopora- Cestriensis, Prout (1858), Trans. St. Louis Acad. Sci., I., 448, pi. 

 XVIII., figs. 2a, b; Meek and Worthen (1870), Proceed. Acad, Nat. Sci., Philad., 15 ; 

 Palaeont. Illinois, pi. XXIV., figs. 14a-c ; Meek (1874), Am. Jour. Sci. and Arts, 486. 



Among the specimens from the Lower Coal Measures at Flint Ridge, 

 near Newark, Ohio, there is a Synocladia agreeing so nearly with S. bise- 

 rialis of Swallow that I am inclined to regard it as a variety of that 

 species. It grows in very rapidly spreading, foliated, or possibly widely 

 infundibuliform expansions, the stems seeming to radiate from the same 

 point, and throwing off on each side lateral branches, which also give 

 off, in the same way, lateral branchlets. The dissepiments, as in the 

 typical forms of S. biserialis, are smaller than the primary and secondary 

 branches, and strongly arched or angulated in passing across, while they 

 give origin to intermediate branches about as often as in the typical 

 specimens of 8. biserialis, as in the latter there are only two rows of pores 

 on each branch and stem, with minutely nodose mesial ridge or carina 

 between. The pores on the dissepiments are arranged much as in S. bise- 

 rialis, as is also the case with the fenestrules. 



The principal differences between these specimens and good examples 

 of S. biserialis from Kansas and Nebraska are the following : In the first 

 place, the entire structure of the form under consideration is more deli- 



