in MeliceititidcU and other Fossil Bryozoa. 51 



closed by an operculum, and all above this is tlie equivalent 

 of the peristome. In recent forms a better name is required, 

 so that it can be a})j)lied whether there is a projection above 

 the zoarium or not. 



This vestibule may be well seen in my figure * of Adeo- 

 nella atlantica, B,, which should be compared with some of 

 Ulrich's. It also occurs in Porina and very well marked in 

 ScMzoporellachallengeria, Watersf; other numerous instances 

 could be given of the same thing in recent and fossil species. 

 At the oral aperture there is often a small calcareous projec- 

 tion for the attachment of the operculum, which in Scliizo- 

 porella challenger ia^ W., is so distinct that it may well be 

 called a hemiseptum ; and a similar projection is figured in 

 Bifaxaria denticulata^ B.J 



Many of Ulrich^s figures remind us very closely of the 

 structure in recent forms ; but there are also several with a 

 series of hemisepta, and it is very difficult to understand what 

 these may mean, so that we may withhold judgment as to 

 whether all that are grouped under Cryptostomata will prove 

 to form a suborder. On the other hand, there seems good 

 reason for thinking that a large number of Palaeozoic forms 

 previously placed with Cyclostomata really show greater 

 afiinities with Chilostomata. 



Since Mr. Ulrich's paper was written I have recorded the 

 fact that in Chilostomata there may be a closure exactly 

 resembling that known in several Cyclostomata, and that it 

 may exist above the oral (opercular) aperture §. Closures are 

 known in many of the Palseozoic fossils ; but these Mr. 

 Ulrich calls opercula, a use of the term against which I must 

 strongly protest, as " opercula " should only mean the 

 movable chitinous cover as known in the Chilostomata. 

 These closures seemed formerly to indicate relationship with 

 the Cyclostomata, but now, knowing them in the other sub- 

 order, their presence cannot be considered to weigh against 

 Mr. Ulrich's views. 



Melicertites royana^ sp. n. 

 (PI. VI. figs. 2, 4, 5, 6, 11.) 



D'Orbigny described Multinodelea tuherosa from several 

 localities in the French Senonian, and among others from 



* Supp. ChaU. Rep. pi. ii. fig. 20. 

 t Loc. cit, pi. ii. fig. 25. 

 X Loc. cit. pi. ii. lig. 31. 



§ " North Italian Bryozoa," Quart. Journ. Geol. Sop. vol. xlvii. p. o 

 kc, pi. iii. fig. 4. 



4* 



