ON CRETACEOUS POLYZOA. 379 
Etheridge were proposed by M. d’Orbigny for his elaborate classifica- 
tion of the Cretaceous Bryozoa of France,! it may be well to preface the 
following analysis with the latest arrangement of the Cyclostomata. In 
1887 Dr. Pergens, of Belgium, spent several months in the study of 
the d’Orbigny collection of Bryozoa, now preserved in the Natural 
History Museum of Paris. Since d’Orbigny completed his work some of 
the examples have become useless as types ; that is to say, some of the 
labelled examples do not correspond with the description and figures of 
his text and atlas. The names of the doubtful species, however, are 
preserved by Dr. Pergens in a separate list ; whilst others are rede- 
scribed and re-illustrated ; and in afew cases new names are given to 
examples which were only partially described by the author. Only the 
first part of the revision, the Cyclostomata, is published as yet ;? but the 
following synopsis of the family and generic arrangement adopted by 
Dr. Pergens will enable the student to appreciate, more fully than he 
otherwise would, the value of d’Orbigny’s labours on the Polyzoa, 
especially so when it is stated that of the Cyclostomata alone Dr. 
Pergens catalogues, as good species, about 253; besides which there 
are at least 75 doubtful forms also catalogued. 
CYCLOSTOMATA (pars), Busk. 
Division (A.), SoLenoporina, Marsson. 
I. Family Cristipz.—Genus: Unicrisia, d’Orb. 
Il. Family Drastororips.—Genera: Stomatopora, Bronn. Diastopora, 
Lamx. Cellulipora, d’Orb. Discosparsa, d’Orb. Ditawia, 
Hagenow. 
II. Family Ipmonr1pm.—Genera: Reptotubigera, d’Orb. Semiclausa, 
d’Orb. Reptoclausa, d’Orb. Idmonea, Lamx. Filisparsa, 
@VOrb. Filicavea,d’Orb. Filicrisina, d’Orb. Hornera, Lamx. 
Spiroclausa, d’Orb. Reticulipora, d’Orb. Retecava, d’Orb. 
Bicrisina, d’Orb. 
IV. Family Evtatopsori2.—Genera : Entalophora, Lamx. Spiropora, 
Lamx. LPeripora, d’Orb. Bidiastopora, d’Orb.  Sulcocava, 
@Orb. Mesenteripora, Blainy. Heteropora, Blainy. 
V. Family Fasciceripz.—Genera: Filifascigera, Reptofuscigera, Semi- 
tubigera, Multifascigera, Semifascipora, Discofascigera, Fasciculi- 
pora, Osculipora, Cyrtopora, Frondipora, Fascipora, Plethopora. 
—All d’Orbigny. 
VI. Family Licuenoporrpm.—Genera: Conotubigera, d’Orb. Apsendesia, 
Lamx. Multicavea, d’Orb. Lichenopora, Defr. Multicrisina, 
d’Orb. Stellocavea, d’Orb. 
VII. Family Cyristpm.—Genera: Discocytis, d’Orb. Truncatula, 
Hag. Swpercytis, d’Orb. Semicytis, d’Orb. Oytis, d’Orb. 
Unicytis, d’Orb. 
VIII. Family Crrrororina.—Genera : Reptomulticava, a’Orb.  Cerio- 
pora, Goldf. Echinocava, d’Orb. Clavicava, d’Orb. 
: Paléont. Frang. tome v. ; Terr. Crét. 1850-52. 
* «Revision des Bryoz. du Crétacé, figurés par d'Orbigny :’ Dr. Ed. Pergens, Bull. 
Soc. Belge, Géol. &c. tome ii. pp. 305-400. 1889. 
