PEOBOSCrNA. 
37 
F OREIQX : 
Senonian — Santonian; Saintes, Charente-Inferieure. 
Coniacian ; Tours, Indre-et- Loire. 
Turonian: Les Roches and Yillardin, Loir -et- Cher ; St. Germain, near 
Fleche, Sarthe. 
Figttee. 
PL II. Fig. 10. Part of a zoarium in which the apertures 
are distant ; X 8 dia. Middle Chalk : Chatham. Gamble Coll. 
D. 3844. 
AFFI^^TIZS. 
M. Pergens proposed the trivial name francorum for a Bryozoan 
which d’Orhigny had referred to P. fasciculata (Beuss), but which 
Pergens rightly separated from that form. It is clearly a close 
ally of P. crassa, divaricata, of which it may be regarded as the 
Turonian and Senonian representative. M. Pergens has remarked 
that d’Orbigny’s type of his I. divaricata (pi. 631, figs. 9-11) 
is unlike the figure, and thus it is perhaps useless to compare 
the figure with that of d’Orbigny’s 7. fasciculata, on which Pergens’ 
species was founded. But the two figures, it may he noticed, agree 
in all essential characters, differing mainly by the greater width 
of the zoarial bands, in the divaricata variety. P. crassa, francorum, 
is so closely allied to the specimens of P. crassa, divaricata, from 
Farringdon, that their varietal separation is perhaps of doubtful 
value. 
LIST OF SPECIMENS. 
British. 
D. 3844. A zoarium growing over Micropora, sp., on eckinid fragment. 
Middle Chalk. Chatham. Gamble Coll. Figd. PI. II. Fig. 10. 
D. 3845. A young zoarium, growing on an echinid fragment (on slide). 
Middle Chalk. Chatham. Gamble Coll. 
60,252. With Stomatopora divaricata (Rom.), on Micraster cortestudinarium. 
Middle Chalk. Sussex. Dixon Coll. Figd. as Alecto gracilis, 
pars, by Lonsdale, 1850, in Dixon’s Geol. Suss. pi. xviii. a, 
figs. 1*, Ic. 
D. 4200. With Prohoscina fasciculata (Rss.), var. toucasi (d’Orb.), on 
Echinocorys scutatus. Middle Chalk. Chatham. Gamble Coll. 
D. 3846. A zoarium with Prohoscina fasciculata (Rss.), var. toucasi, on 
Echinocorys scutatus. Middde Chalk. Chatham. Gamble Coll. 
D. 493. A young specimen with Memhranipora, sp. Middle Chalk. Chatham. 
Gamble CoU. 
