250 Cincinnati Society of Natuial History. 



their correct genera. Compare with Jiillings "On Rkckptacu- 

 i.iTKs'' (Palaeozoic Fossils of Canada, 1., p. 378) and Hinde in 

 Jour. Oeol. Soc , Lond. Nov. 1884 p. 395, et seq 



Genus 7, STROMATOPORA, Goldfuss. 1S26. Petrefacta 

 (JermanicTC. Nicholson & Murie. 1877. Jour, Linn Soc. of 

 London. Zoology, XIV., p. 217. (leol. of Ohio, Paktont. vol. 

 II., p. 245. 



Dystactospoih:;ia, S. A. Miller. 1882. Jour. Cin. Soc. Nat. 

 Hist., vol. v., p. 42. 



"Skeleton (' sarcodeme ') consisting of concentric calcaerous 

 lainin;-e, sej)arated by distinct ' interlaminar spaces,' which are 

 crossed by numerous 'radial pillars." In -some cases there are 

 radiating water canals and surface grooves j^laced round minor 

 centers. Sometimes there are seen on the surface the openings 

 of large water canals ('oscula'). 



" Forming irregular masses, sometimes with a foreign body as 

 a nucleus ; spreading out into extended expansions, covered infer- 

 iorly by a thin, striated, calcareous membrane (' epitheca '), or 

 growing in thin layers parasiticallv u])on foreign objects." Nich. 

 and Murie on " Stromatopora and its allies." Ibid. 



'i'he position of this genus has been the subject of much con- 

 trovers)', and the matter is by no means yet settled. It has been 

 placed with the Polyps and with the sponges, but late writers are 

 inclined to regard it as the type of a separate order. See Nich- 

 olson and Murie, Ibid, and others. The following is an arrange- 

 ment of the species of thisgrouj): 



a. MassiTc foiiiis. 



1 S. ixsoLENs, S. A Miller. 



IJystactospotigia insolrns, S. A. Miller. 1882. Jour. Cin. Soc. 

 Nat. Hist., vol. v., p 43, \)\. 2, figs. 2. 2 a />. 



Massive, irregular in form ; outer surface, with radiating 

 canals; internal structure minutely vesicular. 



Locality : Cincinnati. 



This species closely resembles S. granulata, Nicholson and 

 Murie, as described and figured by them in the article referred to 

 above. See their figure, PI. 1, fig. 11. 



Ik Tubular forms. 

 2. S. TUBULARis, U. P. James. 1884. Jour. Cin. Soc. 

 Nat Hist., VII., p. 139, pi. 7, figs. 3, 3 a b. 



