NOETH AMERICAN PARASITIC COPEPODS BELONGING 

 TO THE NEW FAMILY SPHYRIIDAE. 



By Charles Branch Wh^son, 

 Department of Biology, State Normal School, West field, Massachusetts. 



INTRODUCTION. 



This is the fifteenth ^ paper in the series dealing with the parasitic- 

 copeiDOcls in the collection of the United States National Museum, and 

 comprises a new family to be called the Sphyriidae. 



The genera of this family are closely related to the Lernaeidae, 

 but differ in their life history and in several important morphological 

 characters. Instead of disappearing after the copepodid stages, as 

 in the Lernaeidae, the male persists as a pigmy adult, attached to the 

 body of the female, as in the Lernaeopodidae. Hence sexual maturity 

 is not reached during the last copepodid stage, and both sexes are 

 subsequently changed greatly in body form and structure. Similarly 

 fertilization does not take place previous to the attachment of the 

 female to her host, but after that event and the metamorphosis which 

 follows it, and the spermatophores are attached to the vulvae in the 

 usual manner. The females become even more grotesque and bizarre 

 than those of the Lernaeidae, so that in spite of their paucity of species 

 the genera surpass all the other parasitic copepods in morphological 

 transformations. It is to be regretted that no material is available for 

 the life history of any of the genera, since it probably differs in several 

 essential particulars from any yet recorded. But unfortunately all 

 the species are parasites of fish which frequent the open ocean, and the 

 great majority of which are found only at considerable depths. Con- 

 sequently the developmental stages are very difficult of access, and the 



1 The 14 preceding papers, all of which were published in the Proceedings of the United 

 States National Museum, are : 1. The Argulidae, vol. 25, pp. 635-742, pis. 8-27. 2. De- 

 scriptions of Argulidae, vol. 27, pp. 627-655, 38 text figures. 3. The Caliginae, vol. 28, 

 pp. 479-672, pis. 5-29. 4. The Trebinae and Buryphorinae, vol. 31, pp. 669-720, pis. 

 15-20. 5. Additional Notes on the Argulidae, vol. 32, pp. 411-424, pis. 29-32. 6. The 

 Pandarinae and Cecropinae, vol. 33, pp. 323-490, pis. 17-43. 7. New Snecies of Calignae, 

 vol. 33, pp. 593-627, pis. 49-56. 8. Parasitic Copepods from Pacific Coast, vol. ,35, pp. 

 431-481, pis. 66-83. 9. Development of Achtheres ambloplitis Kellicott, vol. 39, pp. 

 189-226, pis. 29-36. 10. The Ergasilldae, vol. 39, pp. 263-400, pis. 41-60. 11. Descrip- 

 tions of New Genera and Species, vol. 39, pp. 625-634, pis. 65-68. 12. Descriptions of 

 New Species, vol. 42, pp. 233-243, pis. 30-34. 13. The Lernaeopodidae, vol. 47, pp. 565- 

 729, pis. 2.5-50. 14. The Lernaeidae, vol. 53, pp. 1-150, pis. 1-21. 



Proceedings U. S. National Museum. Vol. 55— No. 2286. 



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