NORTH AAIERICAN PARASITIC COPEPODS BELONGING 

 TO THE LERNAEOPODIDAE, WITH A REVISION OF THE 

 ENTIRE FA^^IILY. 



By Charles Branch Wilson. 



Department of Biology, State Normnl School, Westfield, Massachusetts. 



INTRODUCTION. 



The present is the eleventh^ paper in the series based on the 

 collection of parasitic copepods in the United States National Mu- 

 seum and deals with the family Lernaeopodidae. 



For several reasons the necessity of supplemental study has been 

 greater than in connection with any of the f amihes previously treated. 

 The Lernaeopodidae are soft-bodied, without any chitin framework, 

 external or internal, to hold them in shape. Consequently they shrink 

 and often become so distorted during preservation that the museum 

 specimen gives very httle idea of the original. Most of the species 

 are transparent when ahve, and much of their internal anatomy can 

 then be plainly seen. But in a preservative they become opaque and 

 require dissecting or sectioning before anything can be learned with 

 regard to their internal structure. 



Fmally a knowledge of both sexes of the various genera, and of 

 the developmental stages through which the larvae pass has been 

 found necessary for the estabhshment of a rational basis of classifica- 

 tion. And the greater bulk of such information must be obtained 

 outside of a museum collection. 



The development of the family was worked out at Lake Maxin- 

 kuckee, Indiana, during the summers of 1906, 1908, and 1909, and 

 has abeady been pubhshed as the ninth paper of the present series. 



Isolated developmental stages and the males of many species were 

 obtained at Beaufort, North Carohna, while working for the United 



'The ten 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. Descriptions 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 Euryphorinae, 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 Cecropmae, vol. 33, pp. 323-490, pis. 17-43. 7. New Species 

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

 431-481, pis. 66-83. 9. Development of AcMheres amblopUtis Kellicott, vol. 39, pp. 189-226, pis. 2&-3G. 

 10. The Ergasilidae, vol. 39, pp. 263-400, pis. 41-60. 



Proceedings U. S. National Museum, Vol. 47— No. 2063. 



565 



