532 PALEONTOLOGY OF ILLINOIS. 



This is the only species of the genus thus far described. The 

 obliquity of the tubes at once distinguishes it from any Ptilo- 

 dictyoid know to me. The associated P achy diet y a, splendens 

 alone sometimes approaches it in that respect. 



Position and locality: Cincinnati group, Wilmington, 111. 



^NTRAPORA Hall, 1881. 



Trans. Albany Instit. vol. X, p. 157. 

 (For generic diagnosis see page 394.) 



INTRAPORA COSCINIFORMIS Nicholson. 



PL XLIII, llg. G, 6a. 



Ptilodictyacoscini/ormis'Nich. 1875. Geol. Mag. n. s. vol. II, p. 35, PL II, fig. 2-27>. 

 Ptilodictyacosciniformis'NiQh. 1875. Kept. Pal. Ont. p. 80, PL II, flg. 2a, 2&. 



Although differing considerably in its mode of growth from 

 /. puteolata Hall, the type of the genus, thin sections as figured 

 prove them to be congeneric. The zoarium resembles that of 

 Coscinium Keyserling. * 



Position and locality: Hamilton group; Arkona, Canada. 

 It should be searched for in the Illinois and Iowa exposures of 

 the formation. 



STiCTOPORELLAUlrich, 1882. 



(Jour. Cin. Soc. Nat. Hist. vol. V, p. 152.) 

 (For generic diagnosis see page 394.) 



STICTOPORELLA BASALTS Ulrich. 



PL LXXV, flg. 5-5&. 



Zoarium attached to foreign bodies by a large spreading, 

 thin, basal expansion, from which arise irregular inosculating 



*Since writing the above, Vol. 6, Pal. N. Y., has appeared. In this work Prof. Hall 

 proposes a new genus, Coscinella, for a cribrose form which, if indeed It is not the 

 same species, is at any rate congeneric with Nicholson's P. cosciniformis. I question 

 very much whether Coscinella can stand as distinct from Intrapora. On the other 

 hand, the relationship to Coscinium is remote. 



