﻿r 6 



Cincinnati Society of Natural History. 



shaped smaller cells. Nearer the surface the latter are no longer to 

 be determined, being here filled by a secondary deposit. Near the 

 united median laminae in longitudinal sections their vesicular char- 

 acter is very distinct. Diaphragms apparently wanting. 



Type: C. occelata, Ulrich, Vol. v.. Pi. VIII., figs. 3, 3a; and Vol. 

 vii., PI. II., figs. 3, 3a. 



The species of this genus, as now established, are interesting on 

 account of their external resemblance to Stictopora, Hall. One of the 

 species now referred to Cystodictya (Stictopora gilberti, Meek) was 

 allowed to remain in that genus, even after I had prepared a tan- 

 gential section. It is true my material was poor, the zoarium having 

 been replaced by pyrites of iron, which in a great measure destroyed, 

 what now prove to be, the most important characters. Besides the 

 section passed through the zoarium just below the surface, where the 

 vesicular interstitial tissue can not be determined under even the 

 most favorable circumstances. Much better material, since obtained, 

 from which excellent sections have been prepared, now enable me to 

 rectify the error, and place the species where it really belongs. The 

 small lip, which, as is the case in all the species of the genus, consists 

 of a crescentic elevation on the outer margin of the cell aperture, is 

 very distinctly preserved. The two ends of the lip project more than 

 usual into the zooecial cavity. All of the internal characters ob- 

 served are well shown on PI. II., by figs. 5, 5a and 56. 



Mr. G. E. Vine has proposed the generic name Arcanopora for 

 Phillips* Flustra (?) parallela. I have identified this species in the 

 Keokuk Group of Kentuck}^. The American specimens, though a little 

 larger, agree closely in other respects with authentic British examples. 

 The species is, however, a true Cystodictya, and in consequence 

 Arcanopora can not stand.* Cystodictya parallela, as it should now 



* In the same report Mr. Vine also proposes the family Arcanoporidce, of which he makes 

 his Ptilodictya lonsdalei the type. This species he also makes the type of Ptilodictya, 

 altnough the fact is unquestionable that Lonsdale founded the genus upon Goldfuss' Fltts- 

 tra lanceolata. But such a substitution of types is entirely out of the question, and not to 

 be considered for a moment. Furthermore, his fam . Arcanoporidce, in its type, is an exact 

 synonym for Zittel's P tilodictyonidm, since P. lonsdalei is a Ptilodictya. and that genus is 

 the type of Zittell's family. This is a needless duplication of names, and with my work on 

 that family before him, is really inexcusable. I used and defined the genus Ptliodictya as 

 typified by the P. lanceolata, Goldf . sp., which is also Lonsdale's type. Mr. Vine charges 

 that the characters which 1 give as a diagnosis are not those of Lonsdale. To this I an- 

 swer, that the characters he ascribes to the genus are no more Lonsdale's than are mine, 

 and because that author misunderstood the characters of his genus is certainly no reason for 

 me to do likewise. Mr. Vine's conclusions on British Bryozoa, in so far as they have refer- 

 ence to palaeozoic forms, differ in most cases from my own. Their faultiness is often so mani- 



