Prof. M'Intosh on the External Aspect of the Tunny, 523 



Fig. 5. Tangential section of a specimen of R. crinalis, Schliit (?), en- 

 larged twelve times, from the Middle Devonian of Teignmouth. 

 The specimen consists of two superposed layers or colonies, of 

 which one is in the *' steUimicam " state, while the other is 

 normal. The former is here figm'ed. 



Fig. 6. Vertical section of the normal layer of the specimen just referred 

 to. The tubes in this layer are larger than those in the layer 

 represented in fig. 5, and certainly belono- to R. crinalis, 

 Schliit. ' 



Fig. 7. Tangential section of Rhaphidopora crinalis, Schliit, (?), from the 

 Middle Devonian of Dartington (coll. A. Champernowne), en- 

 larged twelve times. 



Fig. 8. Vertical section of the same, similarly enlarged. 



Fig. 9. Tangential section of Rhaphidopora (?) sp., from the Middle 

 Devonian of Teignmouth, enlarged twelve times. 



Fig. 10. Vertical section of the same, similarly enlarged. 



L. — Additional Remarks on the External Aspect of the Tunny. 

 By Prof. W. C. M'lNTOSH, M.D., LL.D., F.E.S., &c. 



The head and some other parts of the specimen of Orcynus 

 thynnus mentioned in the ' Annals ' for April were reserved 

 for a subsequent communication, and hence no special allu- 

 sion was made to the teeth. These of course occur on the 

 vomer, in which respect, as my friend Mr. Day (whose valu- 

 able and long-continued labours amongst the fishes of our 

 own and foreign countries would alone command respect) 

 says, it differs from such as the bonito {Thynnus pelanujs)j 

 a very good example of which was caught near St. Andrews, 

 and is now, thanks to Dr. J. Moir, in the University Mu- 

 seum. Mr. Day's drawing of the teeth was not specially 

 alluded to otherwise than by the general statement that " the 

 teeth are somewhat fancifully represented in all the figures.^' 

 The facts are that in his plate about eighteen or twenty teeth 

 occur in a lateral view along the premaxillge and maxillge, 

 and about fourteen or fifteen in the mandible. In the adult 

 male about fifty occur in each of the series above mentioned. 

 A similar criticism applies to his illustration of the den- 

 tition of the bonito. 1 know it is very difficult to give an 

 adequate representation of such a range of small teeth in a 

 figure of the size of Mr. Day's, and only allude to this to indi- 

 cate that accuracy was the sole aim of my remarks. 



In regard to the dorsal spines * there is a decided diver- 

 gence between the figure in Day's ' British and Irish Fishes ' 

 and the example at !St. Andrews, since the first spine is much 



* These are thirteen in number. 



36* 



