THE SHARKS AND RAYS OF BEAUFORT. NORTH CAROLINA. 



By LEWIS RADCLIFFE, 

 Scientific Assistant, United States Bureau of Fisheries. 



Contribution from the United States Fisheries Biological Station, Beatxfort, N. C. 



J- 



INTRODUCTION. 



The present report deals with the species of sharks and rays of the Beaufort region 

 and includes two species from the Gulf Stream near by. It is intended primarily to 

 serve as a laboratory guide to investigators in this field. The demand for a work of 

 this character has been augmented by the addition to the fauna of a number of little- 

 known species not previously reported from the eastern coast of the United States, by 

 lack of adequate descriptions in some instances and inaccessibility of literature in 

 others. The latest descriptive report on the species of the North Carolina coast con- 

 tains but 1 8 of the 37 listed herein. 



This report was begun at Beaufort in the summer of 191 2 and continued inter- 

 mittently through the summers of 1913 and 1914. It is not the intention to supply 

 complete descriptions for each species, but to furnish data of a character generally 

 lacking in papers on the subject and to make the report of special value as a field manual. 

 For the most part, descriptions and illustrations " are based on material from this 

 region; for completeness material has been obtained wherever possible. The report 

 contains working keys and aims to include in the synonymy of each species all pub- 

 lished references on the subject for this region and no others. The species are arranged 

 in accordance with the classification of Dr. Samuel Garman in "The Plagiostomia" 

 (Memoirs Museum Comparative Zoology, vol. xxxvi, 1913, in two parts), and the 

 nomenclature used in that report has been adopted. 



Many of the sharks and rays are too large to preser\^e or even transport to one's 

 laboratory. The question of what notes should be taken or what is the minimum of 

 material that must be preserved to insure identification of the form often arises. The 

 writer finds that, in addition to the usual field notes, if the jaws and a piece of the 

 shagreen below the first dorsal are preserved, these are all that will be required to 

 identify the sharks. In most species the form and sculpturing of the dermal denticles 

 from a definite body region appear to vary little, if any, with age; in others age 

 differences appear. The amount or extent of variation for all species could not be 

 determined with the limited amount of material obtainable. The denticles from the 

 side of the body below the first dorsal have been used in every case in which they 



o The drawings were made by Mrs. £. Beimett Decker, ofWashington.D.C; the photographs of jaws, embryos, and adults 

 by the author. 



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