A canthocephala 7 E 



Echinorhynchus gadi Miiller, 1776. 



Over fifty specimens of this species were obtained from fish specimens 

 collected by Dr. R. M. Anderson at Banks peninsula, Bathurst inlet, Northwest 

 Territories, May 18, 1916. A single large specimen was taken from the stomach 

 of the Cod, Gadus callarias Linnaeus, at Station 48c (Banks peninsula). The 

 remaining worms came from the California Tomcod, Microyadus proximus 

 (Girard), at Station 486 (Banks peninsula, same date and place as above). 

 As is customary in this species, the specimens vary greatly in size. Those of 

 the present collection range from about 8 mm. to over 50 mm. in length. 



This is one of the few species of Acanthocephala common to hosts both of 

 Europe and of America. Under the name E. acus Rudolphi, this species has been 

 reported frequently by Linton from numerous species of fishes from the Atlantic 

 coast of North America, including Gadus callarias, and also from Microgadus 

 tomcod which is closely related to M. proximus. The writer has also examined 

 specimens from both of these last-named hosts and has compared them with 

 individuals from European hosts and with the arctic representatives. Speci- 

 mens from all three localities undoubtedly belong to the same species. 



CONCLUSIONS. 



The Acanthocephala collected by the Canadian Arctic Expedition comprises 

 two typically North American species of the genus Echinorhynchus parasitic 

 in fresh-water fishes, one species of Echinorhynchus common to marine fishes 

 of both Europe and America, and a fourth species of the genus Filicollis from the 

 King Eider which shows distinctly closer affinities to the previously described 

 North American representative of the genus than to the European. There is no 

 evidence indicating any tendency toward a mixing of American and European 

 species of Acanthocephala in the arctic regions. The evidence is too frag- 

 mentary to permit of any statements of the general distribution of members of 

 this group within the arctic circle. 



LITERATURE CITED. 



Goeze, J. A. E. 1782. Versuch einer Naturgeschichte der Eingeweide-wurmer thierischer 



Korper. Blankenburg. 

 von Linstow, O. 1905. Helminthen der Russischen Polar-Expedition 1900-1903. Mem. 



Acad. Imp. Sc. St. Petersbourge, Serie 8, Class Physico-Math., 18:1-17. 

 Ltihe, M. 1904-05. Geschichte und Ergebnisse der Echinorhynchen-Forschung bis auf West- 



rumb (1821). Zool. Anna!., 1:139-250; 251-353. 



1911. Die Acanthocephalen. Die Siisswasserfauna Deutschlands, Heft 16. Jena. 

 Van Cleave. H. J. 1916. Filicollis botulus, n. sp., with notes on the characteristics of the genus. 



Trans. Amer. Micros. Soc. 35:131-134. 

 1918. The Acanthocephala of North American Birds. Trans. Amer. Micros. Soc., 



37:19-48. 

 1919. Acanthocephala from the Illinois River, with descriptions of species and a synopsis 



of the Family Neoechinorhynchidae. Bull. 111. Nat. Hist. Survey, vol. 13, No. 8. 

 Ward, H. B. and Whipple, G. C. 1918. Fresh-water Biology. John Wiley and Sons, New 



York. 



