130 Part III. — Twenty -sixth Annual Re'port 



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

 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 {Gachis 



ceglefinus). The Scientific Proceedings of the the Dublin Royal Society 



[Read 1893.] 

 Cunningham. — " Marketable Marine Fishes." London, 1896. 

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

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



Annual Eeport of the Fishery Board for Scotland ior 1900 "(1901), Pt. III., 



p. 284. 



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



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

 Scotland for 1901 (1902), Pt. III., p. 539. 



GuNTHER. - ' ' Catalogue of the Acanthopterygii Pharyngognathi 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. XIII. , 1874, p. 138 

 [Gadus aryenteus, etc-.l. 



HoEK. — " Catalogue des Poissons du Nord de I'Fjurope, avec les Noms vidgaires 

 dont on se sert dans les Langues de cette Region." Conseil permanent 

 Internationcd peur V Exploration de la Mer. Publications de Circonstance, 

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



Holt and Calderwood. — " Survey of Fishing-Grounds, West Coast of Ireland, 

 1890-1891. Report on the Rarer Fislies" (PI XXXIX. to XLIV.). 

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

 1896, p. 361 [Gadus poutassou, G. esmarki, G. argenteus']. 



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

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

 Gadus saida, and description of the yoimg of saida.] 



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



Meddelser fra Kommissionen for Havundersogelser. Serie, Fiskerie. Bd. I., 

 Na. 7. Copenhagen, 1905. [Otoliths of G. potitassou, saida, callarias, 

 and vire7is.\ 



Johnstone, J.— "The Food of Fishes." No. XV. Report for 1006 from the 

 Lancashire Sea-Fisheries Laboratory, University of Liverpool, and the Sea- 

 Fish Hatchery at Piel. Liverpool, 1907, p. 216. [Includes the food of 

 Gadus callarias]. 



KoLREUTER. — " Descriptio piscis e Gadorum genere russisNawagadicti,historico 

 anatomica." Novi Commentarii Academire Scientiarum Imperialis Petropoli- 

 tance. Tom. XIV., pro anno 1759. Petropoli, 1770. [Specific description 

 and figure of G. navaga. ] 



Lei^echtn. — "Descriptio piscis e Gadorum genere russis Saida dicti." Novi 

 Commentarii Academice Scientiarum Imperialis Petropolitance. Tom. XVII. , 

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

 G. saida]. 



