BAL^INID^E, 21 



Museum ; it is figured by Yan Beneden in the Ann. Mus. 

 R. Hist. Nat. Belg. vol. iv. pt. 2, pi. xix. figs. 1-4. 



Purchased, 1883. 



M. 1249. Cast of the right tympanic. The history of the original 

 is the same as that of the last specimen ; and it is figured 

 by Van Beneden, op. cit. figs. 9-12. Purchased, 1883. 



46686. The nearly perfect left tympanic of an immature individual ; 

 from the Red Crag of Woodbridge, Suffolk. This speci- 

 men has not been rolled, and its owner evidently lived 

 during the deposition of the Red Crag. Purchased, 1875. 



M. 3509 a. Cast of the slightly imperfect right tympanic. The 

 original (woodcut, fig. 8), which has not been rolled, was 



Balana primigenia. The right tympanic; from the Bed Crag of Suffolk. . 

 (From the ' Quart. Journ. Geol. Soc.') 



obtained from the Red Crag of Suffolk, and is in the 

 possession of "W. Colchester, Esq., of Ipswich. The 

 obliquity of the inner wall is less marked than in No. 

 M. 1248, and agrees in that respect with No. M. 1249 ; 

 the specimen is described and figured by the writer in the 

 ' Quart. Journ. Geol. Soc.' vol. xliii. p. 9, woodcut fig. 1, 

 the figure being reproduced here. 



Made in the Museum, 1886. 



Variety B. 



The obliquity of the superior border of the inner wall of the 

 tympanic is extremely developed, so that the structure of this bone 



