A CONTRIBUTION TO THE ANATOMY OF DINOBOTH- 

 RIUM, A GENUS OF SELACHIAN TAPEWORMS; WITH 

 DESCRIPTIONS OF TWO NEW SPECIES. 



By Edwin Linton, 



0/ the University of Missouri, Colwnbia, Missouri. 



In 1S89 P. J. van Beneden described an interesting cestode from 

 the mackerel shark (Lamna cornuVica) under the name Dinohoth- 

 num septaria} 



The species has been recorded from the same host by Loennberg^ 

 and b}^ Scott.^ Loennberg gives detailed description of the scolex 

 and of immature proglottides. Scott publishes a brief description 

 of the species and a protograph of a specimen collected by him. 



Strobiles with adult, or ripe, proglottides were not seen by any 

 of the above-named authorities. 



I am indebted to Dr. Maurice C. Hall, of the Zoological Division 

 of the United States Department of Agriculture, for photographic 

 copies of Loennberg's papers. 



Tliis paper is a contribution from the laboratory of the United 

 States Bureau of Fisheries, Woods Hole, Massachusetts, and the 

 zoological laboratory of the L^niversity of Missouri. 



On September 1, 1903, 1 collected some cestodes from a small man- 

 eater shark, of which no description was published, but a record was 

 made,^ as follows: 



Dinobothrium septaria Beneden. Host: Carcharodon carcharias Linton, MS 



A t3r[3ographical error appears in the spelling of the generic name, 

 which is printed ^'Dinobothrium." 



During the summer of 1920 I obtained three specimens of a cestode 

 from the bone shark, which also belong to the genus Dinobothrium . 

 Although at first disposed to refer the cestodes of these two lots 

 to the species D. septaria, I found difficulties of two sorts present- 



JBuU. Acad. roy. d. Belg., vol. 17, pp. 68-74, figs. 1-3. 



» Zwei Parasitcn aus Walfischen und zwei aus Lamna comubica. K. vet. Akad. Handl., Stockholm , 

 vol. 24, 1898, pp. 25-28, figs. 11 and 12. Ueber einige Cestoden aus dem Museum zu Bergen, 1898, pp. 

 19-23, fig. 10. 



» Twenty-sixth Ann. Rep. Fisheries Board of Scotland, pt. 2, p. 84, fig. 4, 1898. 



<Bull. Bur. Fish. (1911), vol. 31, pt. 2, p. 58G. 



No. 2401.— Proceedings U. S. National Museum, Vol. 60. Art. 6. 



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