246 , Miscellaneous. 



BASILOSAURUS. 



The following is an extract from a letter from Prof. J. Miiller to 

 Mr. A. Retzius, dated Berlin, March 24, 1847 : — 



" The Hydrarchus, Koch, found in the tertiary formation in Ala- 

 bama, is identical with Harlan's Basilosaurus and Owen's Zeuglodon 

 cetoides^. The crowns of the teeth, with which Owen was not ac- 

 quainted, have a great resemblance to those of the Seal ; in the max- 

 illary teeth they are cutting and many-pointed ; most of the maxillary 

 teeth have double roots, but the anterior has, as in the Seals, only a 

 single root. In the anterior part of the jaw are found conical curved 

 teeth, viz. an incisive and a canine, at least this is the case with the 

 under jaw. 



" As such teeth as those which are found in the Hydrarchus oc- 

 cur in the tertiary formation in Malta, we may conclude that this 

 animal belongs likewise to the tertiary formation of that island. 



** I think I can positively show that the Hydrarchus is not a rep- 

 tile, but a mammal belonging to a peculiar extinct family. It has the 

 ear formed as in the mammals, viz. a helix and a tympanic bone as 

 in the Whales. It has moreover two occipital condyles, and in the 

 whole formation of the cranium no trace of reptile structure occurs, 

 but on the contrary everything is as in mammals. 



*' The vertebral column is very peculiar in its structure. The cer- 

 vical vertebrae, probably more numerous than in any other mammal, 

 are without perforations in their transverse processes ; the ribs are 

 only attached to the transverse processes of the vertebrae ; at the 

 central and posterior part of the column the bodies of the vertebrae 

 are unusually long, and must both at the anterior and posterior part 

 of the extremities have been cartilaginous, inasmuch as we find here 

 beneath the bony shell a mass of pure stone, while the central part 

 of these vertebrae consists wholly of bone." — SilUman's Journal for 

 Nov, 1847. 



Additional Note on a paper on Porcupines. 

 By J. E. Gray, Esq., F.R.S. &c. 



In my former paperf I was unable to give the country of Acanthion 

 Cuvieri. Mr. Frazer has since brought a skull and two living spe- 

 cimens of this species from Algiers ; the latter are now in the Gar- 

 dens of the Society, and Mr. Whitfield has brought others from the 

 Gambia. In the number of the Journal of the Asiatic Society of 

 Calcutta for August 1847 just arrived (p. 772. t. 32), I observe that 

 Mr. Hodgson has described a new species of Indian Porcupine under 

 the name of Hystrix alopcBus, called AnchoUa by the natives, which 

 is certainly an Acanthion, and most probably my A. Hodgsonii ; if so, 

 the latter name will have the priority, as having been published in 

 July. — From the Proceedings of the Zoological Society, Nov. 9, 1847. 



* Phocodon, Agassiz. Squalodon, Grateloup, in Leonhard and Bronn's 

 Jahrbuch fiir Mineralogie, 1841, p. 830. 

 t Ann. Nat. Hist. vol. xx. p. 349. 



