160 
to have been found fossil about Senam, in Etruria. Mr. Montague 
discovered this fossil among the Sienna minute fossils also. 
The same gentleman has also received it, in a recent state, from the 
shores of Kent and Devonshire ; and he has found some specimens of 
Sertularia abietina, taken in the deep by trawling, covered with them. 
In the Linnean Transactions, and by Mr. Fichtel, these shells have 
been considered as nautili ; but Mr. Montague observes, that, “ not- 
withstanding such respectable authority, he cannot assent to that 
opinion. No Nautilus is ever sessile; whereas this is never detached 
but by accident, and then the animal dies. Besides, nothing can be 
more irregular in structure, and the Linnsean characters of the 
Serpula admit of its being chambered.” Supp. to Test. Brit. p. 160. 
It is necessary to observe, that a very close agreement will be found, 
on comparison of the figure given by Lamarck of D. vesicularis, 
which I have copied Plate XI. Fig. 1 , with Nautilus injlatus, Plate 18, 
Fig. 3. of Testacea Britannica ; the latter being a non-descript species 
of Nautilus, found by Mr.Montague among sand on the coast of Devon. 
LXXXV. Rotalites. A convex, conical, spiral, multilocular 
univalve, slightly radiated beneath ; the opening marginal, trigonal, 
and rather turning downwards. 
Lamarck divides this genus into four species : R. trochidiformis, B. 
lenticulina, eadem sinistrorsa, R. depressa, and R. discorbula : all of 
which are found at Grignon ; and none exist, he believes, but in a 
fossil state. Plate XI. Fig. 2, represents the lower radiated surface 
of R. trochidiformis ; the upper surface being spiral, and rather 
conical. Plate XI. Fig. 3, represents the upper surface of R. dis- 
corbula ; the form of which shell, together with the circumstance of 
the mouth of this genus turning downwards, out of the line of the 
preceding whirl, and the frequent occurrence of heterostrophes, 
would make them approximate to Nautilus beccarii, but that no 
mention is made of their possessing any siphuncle. 
