In the ' Bulletins of the Belgian Academy for 1867,' vol. xxiv. p. 566, the Vicomte Du Bus describes this form, a fragment of the tusk of which Prof. Van Beneden showed me from the Diestien beds in 1864, as Alachtherium Cretsii. The description is short, and no figure is given ; my Trichecodon is, however, clearly the form described, and the name Trichecodon Huxleyi has precedence by three years.
2. Teeth of Ziphioids. Abundant in all collections ; species undetermined.
3. Teeth of other large Cetaceans ; undetermined.
4. Ear-bones of Baloena and other Cetaceans, including Delphinus, not determined satisfactorily. Specimens of great beauty are in Mr. Whincopp's collection, and would admit of identification.
5-12. Rostra of Belemnoziphius, seven species named. Besides those with MS. names in the British Museum, the collections of Mr. Whincopp, Mr. Canham, and Mr. Baker contain specimens (especially the first-named collection) which probably belong to yet other species, and are more perfect than those which have been named.
13. Rostra of Choneziphius planirostris, Cuvier. A fine specimen in Mr. Whincopp's collection ; one in the possession of Mr. Calvert, of the Strand ; two fragments in the British Museum.
14. Rostrum of Choneziphius Packardi, Lankester, in the Ipswich Museum ; also a less perfect Choneziphius in my collection, perhaps Ch. Cuvieri of Owen.
15 and 16. Teeth of Delphinus. A few in the three principal collections, of probably two species.
17. Squalodon. Long cylindrical teeth, probably referable to this genus, are in collections (see fig. Geol. Soc). A single foliaceous tooth (of the Zeuglodont type of Owen), undoubtedly belonging to Squalodon, probably S. antverpiensis, is in the Rev. H. Canham's collection.
EXPLANATION OF PLATES XXXIII. & XXXIV.
[All the figures, excepting those of Choneziphius, are of the natural size.]
Plate XXXIII.
Figs. 1-4. Four views of the rostrum of a new Ziphioid Cetacean (Choneziphius Packardi) from the Suffolk Bone-bed, near Felixstow, in the Ipswich Museum, presented by Mr. Cobbold. The figures are reduced to one- fourth the natural size, linear ; consequently they do not give an adequate notion of the large bulk and solidity of the specimen, which measures 16-1/2 inches in length.
Fig. 1, viewed from below; fig. 2, viewed from above; fig. 3, viewed from the right side ; fig. 4, viewed from behind.
v c, primitive trough-like cavity of the vomer; l g, left groove of the dorsum ; r g, right groove of the dorsum ; x r g, expansion of the right groove of the dorsum ; s l, superior lateral canal (one on either side) ; i l, inferior lateral canal (one on either side).
Figs. 5 & 6. Third upper premolar of the right side of Hyoena antiqua, from the Suffolk Bone- bed, in the collection of Mr. Baker, of Woodbridge. (Compare the figures of the two other specimens in the 'Annals and Magazine of Natural History ' for 1864, ser. 3, vol. xiii. pl. viii., and vol. xiv. pl. viii.)
