R. M. Brydone—Chatk Polyzoa. ool 
CRIBRILINA FURCIFERA, noy. Pl. XXX, Figs. 6-8. 
Zoarium always adherent. 
Zoecia very variable in size, length ‘5-7 mm., breadth -4—"58 mm. ; 
aperture semicircular, with a stout perforated tubercle on either 
side, and generally two, sometimes three, and rarely four more 
slender perforated tubercles between them round the upper lip; 
the lower lip is much thickened, especially down the centre of the 
zoecium; its upper edge is primarily straight, but frequently 
develops a stout forked projection, the arms of which reach to 
a point where they partly overhang and appear to rest on, but do 
not in fact touch, the stout paired tubercles; at other times it 
develops a blunt denticle only; front wall generally highly arched, 
but varies down to almost flat as in Fig. 8, and covered with radiating 
ribs varying from very fine and numerous as in Fig. 6, to stout and 
few as in Fig. 8, the normal type with fairly fine and numerous ribs, 
only clearly distinguishable round the margins, being represented by 
Fig. 7; the furrows between the ribs are only perforated once, at 
their outer extremity. The side walls of those zocecia in which 
alone they are visible, i.e. those at the edge of the zoarium, are rather 
splayed and have large foramina in them, one of which, at the 
extreme upper end of the zocecium, is quite invariable in its 
occurrence. 
Owcia very large in proportion to the zocecium, of the globose type, 
but with a tendency to become slightly pointed, and with a strongly 
recurved free edge; they arise just above the pair of stout tubercles, 
but envelop the others. 
Avicularia. Small, depressed, slightly conical cells of irregular 
outline, with a sub-central rounded aperture and one or two large 
foramina in the front wall, such as may be seen in Fig. 8, occur 
sparingly but persistently, and may be in the nature of vicarious 
avicularia. 
This species is not uncommon in the IL. cor-anguinum and Marsupites 
zones of Kent and Hants, is common in the Act. quadratus zone of 
Hants and Sussex, and occurs also in the B. mucronata zone of Hants. 
Crrprinina Finiiozatr, nov. Pl. XXX, Figs. 9 and 10. 
Zoarvum always adherent, resembling that of C. furcifera. 
Zowcia small, length -58—-72 mm., breadth -4—"5 mm.; aperture 
circular, but with the lower one-fourth of its circumference cut very 
- sharply back so as to include an arc of a slightly larger circle; front 
wall gently arched, almost smooth, the radiating ribs and furrows 
which fix the generic position being almost obliterated; the outside 
zocecia show very regularly a large foramen almost at the head on the 
sloping surface above the aperture. 
Owcia very large, strongly resembling those of C. furcifera, but 
relatively rather longer and narrower, and with a stronger tendency 
to be pointed. 
Avicularia not observed. 
Occurs sparingly in the Act. guadratus zone in Hants. 
It will be observed that the last three species are none of them 
typical Cribritineg, and in two of them the furrows are wholly 
