130 Part III. — Twenty-sixth Annual Report 



ramus only being present. Smitt says that the concavity in the Inn 

 edge of the tail fin is greater in this species than in ogac. 



There is a small external genital papilla. The head resembles that of 

 merlangus. The growth rings on the scales are well marked. The 

 lateral line is composed of separate scutes behind the beginning of the 

 second dorsal fin. 



The Specific Identity of a Fish. 



The specific identity is not merely the possession of certain external 

 characters, or a matter of certain distances measured on the surface of the 

 body. It extends through the whole of the organism, exhibiting itself in 

 the skeleton, the abdominal cavity and its organs, and in the appearance, 

 edible quality, and flavour of the flesh. The habits of each species, when 

 they are thoroughly known, will probably be found to be very distinct, 

 the mode of life, food, etc., all serving to distinguish one species from 

 another. In a genus all the species will overlap in their modes of life, just 

 as they do in their bodily characters, but in the aggregate of their habits 

 they will be as clearly identified as in their external form and appearance. 



LITERATURE. 



Books. St. John. — "The Osteology and Arthrology of the Haddock (Gadus 



eeglefinus). The Scientific Proceedings of the the Duhlin Royal Society 



[Read 1893.] 

 Cunningham. — " Marketable Marine Fishes."' London, 1806. 

 Day. — " The Fishes of Great Britain and Ireland." Loudon. 1880-1884. 

 Fulton. — " Ichthyological Notes." [Gadus ccrgenteus, G. poutassou.] Nineteenth 



Annual Report of tkt Fishery Board for Scotland for 1900(1901), Pt. III., 



p. 284. 



"Ichthyological Notes." [Gadus (Gadiculus) argenteus occurring ten 



miles off Aberdeen.] Twentieth Annual Report of the Fishery Board for 

 Scotlandiov 1901 (1902), Pt. III., p. 539. 



Gunther. -" Catalogue of the Acanthopterygii Pharyngognafchi et Anacanthini 

 in the Collection of the British Museum."' London, 1862. Vol. IV. 



'• Notes on some Fishes obtained at considerable depths in the North 



Atlantic." Ann. and Mag. Nat. Hist. (4). Vol. MIL, 1874. p. 138 

 [Gadus aryenteus, etc.]. 



Hoek. — " Catalogue des Poissons du Nord de I'Europe, avec les Noms vulgaircs 

 dont on se sert dans les Langues de cettc Region." GonseU permanent 

 International peur V Exploration d( la Mer. Publications de Circonstance, 

 No. 12. Copenhagen, May, 1904. [Distribution ] 



BColt and CaIiDKRWOOD. — " Survey of Fishing-Grounds. West Coast of Ireland, 

 1890- ISM. Report on the Rarer Fishes" (PI XXXIX. to XLIV.). 

 Scientific Transactions of the Dziblin Royal Society. Vol. V. (II), 1893- 

 1896, p. 361 [Gadus poutassou, G. esmarM, G. argenteus]. 



Jensen, Ad. S. — " The Fishes of East Greenland." Meddelser om Grdnland, 

 Vol. XXIX. ( openhagen, 1904. [Contains notes on Gadus ogac and 

 Gadus saida, and description of the young of saida. | 



"I. Otoliths of the Gadus species deposited in the Polar Deep." 



Meddelser fra Kommixxionen for Havivndersbgelser. Serie, Fiskerie. Bd. I., 

 Xa. 7. ('openhagen, 1905. [Otoliths of G. poutassou, saida, callarias, 

 a nit virens. ] 



Johnstone, J. —"The Food of Fishes." No. XV. Report for 1906 from the 

 Lancashirt Sea-Fisheries Laboratory,' University of Liverpool, and thi Sea- 

 Fish Hatchery at I'll. Liverpool, 1907, p. 216. [Includes the food of 

 Gadus callarias']. 



KoLREUTER. — " Deseriptio piscis e Gadorum genere russis Xawaga dicti.historico 

 anatomica." Novi Commentarii Academia Sdentiarum Imperialis Petropoli- 

 tance. Tom. XIV., pro anno l7->9. Petropoli, 1770. [Specific description 

 and figure of 67. navaga.] 



LefecHIN. — "' Deseriptio piscis e Gadorum genere russis Saida dicti." Novi 

 Commentarii Academice Sdentiarum Imperialis Petropolitanee. Tom. XVII. , 

 pro anno 1773. Petropoli, 1774. [Specific description and figure of 

 G. saida]. 



