44 DB. W. G. BIDBWOOD ON THE [Feb. 5, 



we were not able to get any specimen of the Majorcan Hare. 

 Barcelo relates that it was introduced into Minorca by the English, 

 but that it died out there after a short time. It certainly does not 

 occur there now. 



24. Obyctolagus ouniculus L. 



The Eabbit (Ouni in Balearic, Gonejo in Spanish) occurs in all 

 the three islands of the group, but is nowhere very common. 



2. On the Structure of the Horny Excrescence, known as 

 the " Bonnet,'' of the Southern Right Whale {Balam 

 australis). By W. G. Ridewood, D.Sc, F.L.S., 

 Lecturer on Biology at the Medical School of St. Mary's 



Hospital . 



[Eeceived December 18, 1900.] 



(Plate Vl.i) 



The two specimens upon which the following observations were 

 made are those described by Grray in 1864 in the ' Proceedings ' of 

 this Society (p. 170), and in 1866 in the British Museum Catalogue 

 of Seals and Whales (p. 95). They are respectively catalogued 

 at the Natural History Museum, where they are eshibited, as 

 " epidermic excrescence from the median line of the fore part of 

 the head; called by whalers the bonnet," and "smaller specimen 

 of the same"; and they bear the register numbers 64.6.1.15 

 and 64.6.1.6 -. Both were presented to the Museum by Mr. E. 

 W. Holdsworth in 1864. The larger specimen measures 11 inches 

 by 8, and the smaller 6 inches by 2|. A rough woodcut of 

 the former was given by Gray in the ' Proceedings ' of this 

 Society, and in the British Museum Catalogue of Seals and 

 Whales. 



This wart or " bonnet " on the snout has been the object of 

 many ingenious speculations. Gray mentioned it as the opinion 

 of a foreign zoologist, whose name is not disclosed, that the 

 " bonnet " is an excrescence formed by the adhesion of the bar- 

 nacles called Coronula. A. second opinion of the same authority 

 is that it is caused by the irritation of the whale-louse. Mr. 

 Holdsworth suggested that it was a natural development, and was 

 possibly characteristic of the species ; while Owen considered it as 

 due to disease of the outer layers of integument. Beddard, in his 

 recent 'Book of Whales' (1900, p. 136), states that "it gives 

 one the impression that it is a pathological structure, a kind of 

 corn,^ perhaps produced by the animal rubbing itself against rocks, 

 as this species has been observed to do in order to get rid of the 

 barnacles which are apt to infest it." 



1^ For an explanation of the Plate see p. 47. 



■^ List of Oetacea in the British Museum, London, 1885, p. 3. 



