22 FORAMENIFERA. SIDEROLITES. 
with numerous transverse septa, which embrace each other 
with their reflected margins. 
Amplexus Corralloides. Plate II. figs. 38, 39. 
This curious fossil strongly resembles a Zoophite. It is found in the Lime- 
stone, called Black Rock, at Limerick, Ireland. 
ORDER IIT.— FORAMENIFERA. 
Shells multilocular, minute, placed internally in the ani- 
mal, and destitute of an open chamber beyond the last 
partition. 
It is the opinion of Dujardin, that the shells of this order 
should form a distinct class; but until they are better 
known, I prefer retaining them in the situation in which 
they were placed by Lamarck ; but have adopted the order 
formed by D’ Orbigny for their reception. ~ 
TRIBE I.—POLYSTOMATA. 
Shell discoidal ; spire central, with an external chamber 
only, 
Genus IL—VORTICIALIS. — Lamarck. 
Generic Character.— Shell disciform ; spiral, multilocular, 
with contiguous volutions, which are entirely enveloped in 
the external one ; septa transverse, imperforate, and not 
extending from the centre to the circumference ; aperture 
marginal, 
Vorticials strigilata. Plate II. fig. 9. 
Genus Il. — POLYSTOMELLA. — Lamarck. 
Generic Character. — Shel] discoidal, multilocular, with 
continuous volutions, all enveloped in the external one ; 
sides transversely furrowed ; aperture composed of several 
openings variously disposed. 
Polystomella crispa. Plate II. fig. 15. 
Genus III. — SIDEROLITES. — Lamarck. 
Generic Character. — Shell discoidal, multilocular, with 
contiguous volutions, enveloped in the external one ; the 
