CETOTOLITES. 535 



also manifests the Balaenal character in the extension 

 of the origin of the overarching wall around the inner 

 end, throwing the opening of the tympanic cavity back- 

 wards. 



In the account of these Cetotolites, read to the Geo- 

 logical Society,* the vertical notch or indentation of the 

 border of the involuted convexity of the tympanic bone 

 of the Baleena mysticetus is noticed in connection with that 

 character in the Baleena emarginata ; but in the Balaena 

 mysticetus, the involuted convexity does not swell out into 

 lobes at the back part of the bone. 



Professor Henslow observes, " It is not a little remark- 

 able that all these specimens should have been procured 

 within a very narrow compass, for I found none beyond 

 the limits of two contiguous indentations in the cliff, a 

 short distance to the north of Felixstow."-f- Mr. Rose, 

 F.G.S., has, however, since discovered a fractured fossil 

 tympanic bone of the Balana definita in a patch of crag, 

 high up a rather lofty part of the bank of the river Orwell, 

 a short distance below Holywells, Suffolk. The dense tex- 

 ture of this fossil, as of most of the specimens from Fe- 

 lixstow, presented evidence of ferruginous infiltration in 

 a dark layer surrounding the lighter-coloured central part 

 of the bone. The long diameter of this specimen mea- 

 sured three inches and a quarter, its short diameter two 

 inches.! 



* ' Quarterly Journal of the Geological Society,' No. I. p. 40. ( Ibid. p. 36. 



J Numerous other nodules, or pebbles, some cylindrical, some fusiform, with 

 annular, or spiral, or longitudinal convolutions, occur in the Red Crag at Fe- 

 lixstow, which present external indications of animal origin ; and yield, upon 

 analysis, 56 per cent of phosphate of lime. They occasionally contain remains 

 of small crabs and fishes, sharks' vertebra?, for example, like those of the 

 London clay ; and they have been regarded by Professor Henslow, who first 

 called attention to their probable origin, as coprolites. ' Proceedings of the 

 Geological Society," 1 December, 1843, p. 282. 



M M 4 



