BICAVEA, DESMEPOKID^. 
109 
Char.— Z oarium of a narrow peduncle and swollen vase-shaped body, from the 
upper edge of which rise a series of seven tufts {urnula), or sixteen to eighteen 
radial vertical plates Avith miiltiserial apertures on the vertical edge {dilaUita). 
The stem is covered with apertures. 
Distrir. — English : L pper Chalk — Zone of Micraster coranguiniim : Isle of 
AVight. Foreign: Senonian — ^Nraastrichtian : Fecamp, Seine - Inferieure ; 
Meudon, near Paris : Sainte-Colomhe, Manche. 
Aff. — M. Pergen-s has united d’Orbigny’s species, and as he has had the 
opportunity of studAing the type -specimens, it seems advisable to accept his 
decision ; for both urnula and dilatata have vasiform bodies, the difference 
between them being that in the latter the body is much broader in proportion 
to its height; correlated to this flattening is the change of the groups of 
apertures from cylindrical spikes to radial vertical plates ; the apertures in both 
occur above tlie body and not in vertical series down its side. Pergens & 
Meuuier, in their memoir on the Faxoe Bryozoa, included Multicrisina 
cupula in this species as an individual subdivided into three sub-colonies ; 
M. Pergens later, in 1890, however, adopted Avhat seems to me the sounder 
view of separating the two species, li. cupula and B. u>-mda. 
Suborder CANCELLATA, Gregory, 1896. 
[For Diagnosis and reference see Yol. I. pp. 359-60.] 
Family DESMEPORID.E. 
Synonyms. 
Cytisida, pars, d’Orbigny, 1854 ; pars, Pergens, 1890. 
OscuUporidce, pars, IMarsson, 1887. 
Fasciyeridce, pars, Ulrich, 1900. 
Diagnosis. 
Cyclostomata Cancellata with a branched zoarium ; the branches 
are fascicular in structure, and the apertures open in groups 
on the ends of lateral processes or tufts along the stems. 
Affinities. 
The Bryozoa referred to this new family comprise those of 
the Cytisidm of d’Orbigny, in which the zoarium is cancellate 
in structure. It therefore includes most of Semicytis and one 
species of his Truncatula\ most of the Cytisidse are, however, 
non-cancellate, and belong to the Osculiporidae. 
This family is allied to the Horneridae, as most of its members 
have an erect dendroid zoarium, and as the apertures open either 
only on the obverse face or also on the sides of the stems. In some 
cases the apertures are in horizontal rows, as in Sornera. The 
family differs from the Horneridae by its fascicular structure, 
and by its peristomal bundles projecting as tufts above the 
general surface of the stems. 
