58 MAMMALIA. 



has been referred to the above species (Newton, Quart. Journ. 

 Geol. Soc., Vol. XLIL, p. 319, PL xi., fig. 5, 1886). 



The somewhat similar specimen from the Pliocene of Chmsi 

 near Pisa, named Balcena ctrusca by Prof. Capellini (Mem. Ace. 

 Sci. Inst. Bologna, Ser. 3, Vol. III., 1873) has really a different 

 form and the arrangement of the neural arches is not the same. 



Mr. A. Savin has obtained a large Cetacean tympanic bone, 

 from the Forest-bed at East Runton, which resembles that of 

 B balcenopsis figured by Prof. Van Beneden (Ann. Mus. Roy. 

 Hist. Nat. Belg., Vol. IV., Part ii, PI. 3, 1880), but is larger; it 

 also resembles some of the forms referred to B. insignis and B. 

 primigenia ; but as the tympanics of these species are so much 

 alike, and evidently closely allied to the recent B. biscayensis, and 

 as this is the only species at present known in the Forest-bed, 

 the East Runton specimen is provisionally placed in the latter 

 species. 



Balcena biscayensis was formerly abundant on the western 

 coasts of Europe, but appears now to be nearly extinct. 



BAL.ENA AFFINIS, OWEN. 



PLATE VI., FIG. 3. 



This is one of the four species proposed by Sir R. Owen (Proc. 

 Geol. Soc., Vol. IV., p. 283, 1843, and Quart. Journ. Geol. Soc., 

 Vol. I., p. 39, also Brit Foss. Mamm., p. 530, 1846) for the tym- 

 panic bones known to him from the Suffolk Crag, and were placed 

 in the genus Balcena; but subsequently altered to Balcenodon 

 (Brit. Foss. Mamm., table opposite p. xlvi, and Palaeontology, 

 1860, p. 342). Mr. Lydekker thinks this species should be retained 

 in the genus Balcena (Quart. Journ. Geol. Soc., Vol. XLIII.,p. 8, 

 1887) and says : " The tympanic of B. affinis is characterized by 

 its elongated shape and flat anterior surface, its nearly straight 

 inferior border, which is approximately parallel with the superior 

 border of the inner wall, the height of the inner wall at the 

 Eustachian part of the aperture, the produced antero-inferior 

 angle, and the slight thickening of the involucrum." Specimens 

 of this species are to be seen in the British Museum, Museum of 

 Practical Geology, and elsewhere. Balcena affinis is only known 

 in England from the Nodule-bed of the Red Crag of Suffolk ; but 

 specimens precisely similar have been found in the Antwerp Crag 

 and are in the Brussels Museum. 



PRIMIGENIA, r. BENEDEN. 

 PLATE VI., FIGS. 2a, 2b. 



This species was established by Prof. Van Beneden (Bull. Acad. 

 Roy. Belg, Vol. XXXIV., p. 9, 1872, and Ann. Mus. Hist. Nat, 

 Vol. IV., Part 2, p. 66, 1880), for certain large Cetacean bones 



