1864. | DR. J. E. GRAY ON BRITISH CETACEA. 241 
5. LAGENOCETUS. 
The crests of the maxillary bones very thick and close together, 
especially above, where they are flat-topped. The beak of the skull 
horizontal. The hinder edge of the skull lower than the top of the 
crest. Lower jaw straight. 
Lagenocetus, Gray, P. Z. 8. 1863. 
Hyperoodon, Gray, Cat. Cetac. 69. 
This animal has been considered by Eschricht as the male of the 
preceding genus ; but in the ‘ Proceedings of the Zoological Society ’ 
for 1860, p. 425, I have shown that both sexes have been observed 
of each genus. 
LAGENOCETUS LATIFRONS. 
Hyperoodon latifrons, Gray, Zool. E. & T. 27, t. 4; Proc. Zool. 
Soc. 1860, p. 424. 
Hyperoodon butzkopf (male), Eschricht, Ann. & Mag. N. H. 
1852. 
Hab. British seas. Moreton Bay; skull in good condition. Orkney 
(Warwick) ; skull in British Museum. Frith of Forth ; skeleton 
and skull in Mus. Coll. Surgeons, Edinburgh ; female accompanied 
by a young male (Thompson, Ann. & Mag. N. H. 1846, p. 153). 
** Mazillary bones simple; teeth, on the sides of the lower jaw, 
compressed. Ziphiina. 
6. ZipHtivus. 
Lower jaw gradually tapering. Teeth on the sides of the jaw of 
the males large, compressed ; and female small, conical. 
Ziphius, Gray, Cat. Cetac. 70. 
9? Delphinorhynchus, Gray, Cat. Cetac. 72. 
Tympanic bones large, very thick, free edge open, and much 
twisted (see Van Beneden, Mém. Acad. Brux. &vo, xvi. fig. at p. 41 ; 
and Dumortier, Mém.). 
ZIPHIUS SOWERBIENSIS. 
Male. Physeter bidens, Sowerby, Brit. Misc. t. 1, 1805, male ; 
Turton, B. Fauna, 17. 
Diodon bidens, Bell, Brit. Quad. 497. fig. (cop. fr. Sowerby). 
Delphinus sowerbii, Desm. Mam.; Jardine, Nat. Lib. t.12 (cop. 
fr. Sow.). 
Delphinus sowerbiensis, Blainv. in Desm.; Eschricht, Ann. & 
Mag. N. H. 1852. 
Delphinorhynchus bidens, Gray, Ann. & Mag. N. H. 1840. 
Heterodon sowerbyi, Lesson, Man. Mam. 419. 
Ziphius sowerbiensis, Gray, Zool. E. & T. t. 5. f. 3,4, skull; Cat. 
Cetac. 71. 
Mesodiodon sowerbyi, Duvernoy, Ann. d. Sci. Nat. xv. 55, t. 2. f. 2. 
Diplodon sowerbyi, Gervais. 
Proc. Zoou. Soc.—1864, No. XVI. 
