160 



to have been found fossil about Senam, in Etruria. Mr. Montague dis- 

 covered 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 abktina, 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 opi- 

 nion. 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 Linna?an 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 inflatus, Plate 18, Fig. 3, 

 o Testacea Eritannica ; 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 uni- 

 . Valve, slightly radiated beneath; the opening marginal, trigonal, and 

 rather turning downwards. 



Lamarck divides this genus into four species : R. trochidiformis, R. len- 

 ticnlina, 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 XL Fig. 2, represents the lower radiated surface of R. trochidi- 

 formis; the upper surface being spiral, and rather conical. Plate XI. 

 Fig. 3 , represents the upper surface of R. discorbula; 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. 



