532 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 30, 



5. On the Fossil Cranium of Dicynodon tigriceps, Owen, 

 from South Africa. By Prof. Owen, F.R.S., F.G.S. 



(This communication will be published in full in the 4th Part of the 7th vol. of 

 the Society's " Transactions.") 



[Abstract.] 



In this paper Professor Owen described in detail the cranial bones of 

 a large species of Dicynodon^ from South Africa. The specimens 

 described were transmitted by A. G. Bain, Esq., to England in 1849, 

 and are now in the British Museum. The skull surpasses in size 

 that of the largest walrus, and resembles that of the lion or tiger in 

 the great development of the occipital and parietal ridges, the strength 

 of the zygomatic arches, and the expanse of the temporal fossae, — 

 all indicating the possession of the temporal (biting) muscles as 

 largely developed as in the most powerful and ferocious of the car- 

 nivorous mam^malia. Hence Prof. Owen names this species Dicy- 

 nodon tigriceps. Like the smaller forms of Dicynodon, already de- 

 scribed by the author, this species has two long, curved, canine tusks 

 in the upper jaw ; the jaws being otherwise destitute of teeth. 



May 30, 1855. 



The Rev. J. Knowles and James M*Cann, Esq., were elected 

 Fellows. 



The following communications were read : — 



1. Notice of the Occurrence of a Tidal Phenomenon at Port 

 Lloyd, Bonin Islands. By P. W. Graves, Esq., H.M. 

 Consul- General for the Sandwich Islands. 



(Communicated from the Foreign Office, by order of the Earl of Clarendon.) 



[Abstract.] 



At Port Lloyd, west side of Peel Island (one of the Arzobispo or 

 Bonin Islands, lat. N. 27° 20', long. E. 141° 45'), on the morning 

 of the 23rd December, 1854, a sudden rise of tide occurred to the 

 height of 15 feet above high- water mark. It then immediately 

 receded, leaving the reefs entirely bare, and Ten Fathom Hole, in 

 which our vessel was anchored, was turned into a complete whirlpool. 

 The tide continued to rise and fall during the night at intervals of 

 fifteen minutes, gradually lessening in force until evening, when it 

 subsided nearly to its usual level. On the evening of the 25th, the 

 waters were again agitated, and rose to the height of 12 feet, and so 

 continued during the night. On the morning of the 26th the tides 

 became regular. 



The force of the reflux was such that the "What Cheer" was 

 dragged from her anchorage, and was carried out of Ten Fathom 

 Hole at the rate of 8 miles an hour, just clearing the rocks which lay 



* For the description of this genus and the species previously recognized by 

 Prof. Owen, see Trans. Geol. Soc, 2nd Ser., vol. vii. p. 59. 



