148 



Cincinnati Society of Natural History. 



tomata and Cheilostomata, were probably developed. Accordingly, in 

 my scheme of classification I propose the new sub order Trepostomata , 

 It is at present impossible to determine with any degree of certainty 

 the exact limits of the sub-order proposed, but they may be indicated, 

 as it is partially done in the following tabulated list of Bryozoa, pos- 

 sessing one or more of the important characters of the Monticuliporidoe, 

 and Fistutiporidce. 



Of the various characters ol the Monticuliporidce and Fistulipori- 

 dce, we find — 



(1) . Azoarium composed of tubular cells : 

 In the majority of the Cyclostomata, and 

 some of the Cheilostomata. 



(2) . Zoarium divided into "immature" 

 and " mature" regions: In the Cerio- 

 poridce, Busk, Ptilodictyonidce, Zittel, 

 and Stictoporidce, Ulrich. 



(3) . A germinal or epithecal plate ("lame 

 germinale," D'Orb.): In a large num- 

 ber of the Cyclostomata. 



(4) . Diaphragms — 



In several genera of the Ceramoporidce, 

 Ulrich ; and Ptilodictyonidce, Zittel ; 

 and in many of the Cerioporidce, 

 Busk. 



(5) . Vesicular interstitial tissue — 



In Cystodictya, Ulrich (of the Sticto- 

 poridce); and Eridopera, Ulrich, (? a 

 genus of the Ceramoporidce). 



(6) . Interstitial cells — 



In Ptilodictya, Lonsdale (several spe- 

 cies). 



Pachydictya, Ulrich. 

 Phyllodictya, Ulrich. 

 Stictoporella, Ulrich (pits). 

 Graptopora, Ulrich (pits). 

 Ceramopora. Hall. 

 Ceramoporella, Ulrich. 

 Cheiloporella, Ulrich. 

 Crepipora, Ulrich. 



And in the forms arranged by D'Orbi- 



gny, under his family names — 

 Clausidce. 

 Caveidce. 

 Crescisidw. 

 Cytisidcc. 



Also, among the Cheilostomata, in the 

 family Myriozoumidce, D'Orb. 



(7) . Interstitial membrane — 



In Ceramoporella, Ulrich. 



Eridopora, Ulrich. 



Pachydictya, Ulrich. 



Phyllodictya, Ulrich. 



Cystodictya, Ulrich. 



Heteropora, Blainville. 



Defrancia, Bronn. 



Claviclausa, D'Orb. 



Clausimultelea, D'Orb. 



Nearly all the forms placed by D'Or- 



bigny under his family Clausidce. 

 Myriozoum, Donati. 



(8) . Spiniform tubuli — 

 Rhinidictya, Ulrich . 

 Crepipora, Ulrich. 

 Rhombopora, Meek. 

 Bythopora, Miller and Dyer. 

 Species of Heteropora, Blv. 



Small hollow spinelets, supposed to be 

 analagous to the spiniform tubuli, 

 are developed in — 



Membranipora. 



Lepralia. 



Flustrellaria. 



And other genera. 



(9) . Wall inflections and " radiating 



spines" — 



Wall inflections in the Monticulipori- 

 dce are generally (? always) due to the 

 encroachment of the spiniform tu- 

 buli upon the tube cavity. How- 

 ever, in such species of Ptilodictya , 

 as P. maculata, Ulrich, in which no 

 spiniform tubuli are developed, sim- 

 ilar and very distinct inflections are 

 present. The same may be said of 

 certain species of Neuropora. " Ra- 



