299 



Haswellia coronata Reuss 

 Cellaria coronata Rcuss, Fossile I'olyparien d. Wiener 'rerliiir 

 beckens, Haidinger Naturwiss. Abhandl. 

 2ter Band, 1848, p. 62, T. VIII, fig. 3. 

 Eschara gracilis Lanix. Encyc. mclli. p. 375. 



(PI. XYt, iii;. I I)). 



The zocecia elongated, without distinct separating furrows, wilii numerous 

 .scattered pore-canals, which have an inner wholly uncalcified rosette-plalc. The 

 well-chilinized oi)erculuin, Ihe j)0ster of which is not distinctly separated from 

 the antcr, may he called broadly egg-shaped, as it decreases evenly in breadth in 

 its i)roximal hall". It is provided within Ihe margin on each side with a ridge- 

 shaped thickening, which disappears both dislally and proximaily. There is a 

 hinge-tooth on each side. The secondary aperlure is i)road, transversely oval, but 

 has a bean-shaped appearance, because the inner surface of the perislome-tube is 

 provided a little within the proximal margin of the aperture with a low, but 

 broad, triangularly rounded projection. The peristomial pore is elongated in the 

 ordinary zocEcia and round in the ooecia-bearing ones. Each distal wall has nu- 

 merous, uniporous rosette-plates, which owing to the thickness of this wall are 

 situated at the end of long pore-canals. The distal half of each lateral wall is 

 provided with 2 — 3 scattered uniporous rosette-plates situated at the end of short 

 pore-canals, which perforate the wall iii an oblitiue direction, so that the rosette- 

 plate lies on the internal surface of the wall and the entrance to the canal on 

 the external. As in the preceding species the outer part of the lateral wall is 

 perforated by the inner end of a number of pore-canals. 



The ooecia as in the foregoing species are large swellings not sharply marked 

 off from the distal zocrcium. The peristomial pore is round and the projection 

 appearing within the secondary aperlure in the ordinary zoircia is wanting or 

 weakly developed. 



The avicularia, which are very small as a rule, generally seem to have a 

 rounded form. On the circumference of the secondary aperture there are as a rule 

 1 — 3 more or less projecting on the distal margin and 1 — 2 on the proximal. One 

 is also present as a rule on each side or only on the one side a little more prox- 

 imaily, almost halfway between the aperture and the peristomial pore. The last 

 may sometimes reach a fairly considerable size and then have a broadly rounded, 

 somewhat lyre-shaped 0])ening. Further, there may also be 1 — 2 in the proximal 

 part of each zooeciuni. Round the aperlure of the oa'ciuni-bearing zocecia the 

 avicularia are always in smaller number and may sometimes be quite wanting. 



