445 



extinct Ichthyosaurus and the Grampus, being lodged in a wide and moderately deep 

 groove, imperfectly divided into sockets, the septa of which reach only about half-way from 

 the bottom of the groove. 



Mus. Brookes. 



2450. The lower jaw of a female Cachalot (Physeter macrocephalus). 



Each ramus contains twenty-two teeth : the lower jaw also shows a sexual distinction of 

 size, being shorter by one-third than in the male. 



Presented by Fred. D. Bennett, Esq., F.L.S. 



' 



2451. The dentary portion of the lower jaw of a Physeter, said to be of the ' lesser 

 Cachalot ' (Physeter catodon), probably of a young Physeter macrocephalus. 

 No characters in support of the specific distinction can be founded on the 

 present specimen from the teeth, for most of them have belonged to large 

 species of Seal, and have been artificially attached to the alveolar grooves. 



Mus. Brookes. 

 



2452. The right ramus of the lower jaw of a Physeter, the anterior part of which is 



curved strongly inwards and backwards, in consequence of some injury received 

 in youth. Presented by Fred. D. Bennett, Esq., F.L.S. 



2453. A portion of the lower jaw of a Physeter, being a section of its entire thick- 

 ness, exhibiting its dense osseous structure, and its wide vascular and nervous 

 canal. Presented by Fred. D. Bennett, Esq., F.L.S. 







2454. The right petrotympauic bone of a Cachalot (Physeter macrocephalus). It is 

 fractured so as to display the inner surface of the convoluted tympanic bone. 



Presented by George Bennett, Esq., F.L.S. 



2455. The left petrotympanic of the same Cachalot. 



Presented by George Bennett, Esq., F.L.S. 



. 



2456. A lumbar vertebra of a large Sperm- Whale (Physeter macrocephalus). 



Presented by Sir William Blizard, F.R.S. 



2457. A caudal vertebra of a large Sperm- Whale (Physeter macrocephalus). 



Presented by Sir Wittiam Blizard, F.R.S. 



