43 



rior in size to Balcenoptera goropi ; the parietals are longer than in 

 G. dubium. 

 Hob. Europe (Belgium and England). 



M. 3527. The imperfect left tympanic ; from the Antwerp Crag. 



This specimen closely resembles the one figured by Van 



Beneden in the 'Ann. Mus. R. Hist. Nat. Belg.' vol. ix. 



pt. 4, pi. ii. fig. 1. By exchange with the Royal 



Brussels Museum of Natural History, 1886. 



43600. The right humerus ; from the Antwerp Crag. This speci- 

 men resembles the one figured by Van Beneden, op. cit. 

 pi. iv. Purchased. 



46734. The centrum of the axis vertebra ; from the Eed Crag of 

 Woodbridge, Suffolk. This specimen agrees very closely 

 with the one figured by Van Beneden, op. cit. pi. vii. 

 fig. 4. Purchased, 1875. 



Cetotherium dubium, Van Beneden x . 

 Syn. Plesiocetus dubins, Van Beneden 2 . 

 Plesiocetopsis dubius, Brandt 3 . 



This species is intermediate in size between C. brialmonti and 

 C. burtini, many of the bones being very difficult to distinguish from 

 those of the latter, and also resembling those of Megaptera similis. 

 The atlas and axis are less massive than in C. burtini. Two worn 

 tympanics in the Museum of the Royal College of Surgeons (No. 

 2832 A, B) indicate the occurrence of the species in the Red Crag. 



Hab. Europe (Belgium and England). 



M. 3526. The slightly imperfect left tympanic ; from the Antwerp 

 Crag. This specimen agrees precisely with the one figured 

 by Van Benedeu in the ' Ann. Mus. R. Hist. Nat. Belg/ 

 vol. ix. pt. 4, pi. xiv. fig. 14. 



By exchange with the Royal Brussels 

 Museum of Natural History, 1886. 



M. 3526 a. A rather more imperfect example of the left tympanic ; 

 from the Antwerp Crag. 



By exchange with the Royal Brussels 

 Museum of Natural History, 1886. 



1 Bull. Ac. E. Belg. s6r. 2, vol. xxxiv. p. 18 (1872). 



2 Ibid. vol. 1. p. 18 (1880). 



8 Mem. Ac. Imp. St. Petersbourg, vol. xx. p. 146 (1873). 



