2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.60 



sequent to attachment. The grotesque transformations so common 

 in the Lernaeidae and Sphyriidae are entirely unknown here, and 

 there are not the complicated differences in size and morphology be- 

 tween the two sexes. The males are smaller than the females but they 

 never become pygmies, and the structure of the two sexes is so similar 

 that it betrays specific as well as generic identity. 



The material for the present paper has been derived chiefly from 

 the collection of the United States National Museum, which included 

 most of the genera. This material has been supplemented with speci- 

 mens collected by the present author at Beaufort, North Carolina, in 

 1905, while working for the United States Bureau of Fisheries, 

 which include six new species. 



There are also three more of the drawings by J. H. Blake, placed at 

 the author's disposal by the late Dr. Richard Rathbun. Specimens, 

 descriptive notes, and pencil sketches of a new species of Leman- 

 thropus from the Pacific coast came to the author many years ago 

 from Dr. M. T. Thompson. 



The same methods of dehydration and clearing have been used 

 as in the Ijernaeidae and Sphyriidae, and with excellent results. 

 Much of the internal morphology has been determined from these 

 cleared specimens, and they have been supplemented by serial sections 

 of Nemesis^ Eudactyliria^ Diclielesthium^ and Lernanthrojyus. 



As here constituted the family is made up of 20 genera, of which 

 one, Bassettithia, is a new genus name to take the place of one already 

 occupied, and 107 species, of which 9 are new to science. 



The present author has been unable to examine any specimens 

 belonging to the genera No^'ion, Kr0yeria, Congericola, Lampro- 

 glena, Donusa, Bassettithm, Pseudoclavella, Cyhicola, and Ven- 

 triculina. But it has seemed wise to include keys to the species of 

 these genera, based necessarily upon their published descriptions. 



HISTORICAL. 



Abildgaard was the first to notice any of the species belonging to 

 this family. In 1794 he described and figured ^ two new species, 

 which he referred to the genus G aligns and named, respectively, cras- 

 sus and ohlongus. In 1816 Leach, probably without knowing of 

 Abildgaard's description and figures, established a new genus and 

 species upon some specimens from the gill cover of a shark captured 

 on the coast of England, which he named Anthosoma smithii} 

 About the same time or a little later Risso published his " Histoire 

 Naturelle des Crustaces des environs de Nice," in which he described 

 (p. 162) a new species of the genus Caligus^ which he called Caligus 

 imhricatus. Leach afterwards had an opportunity of examining 



* Skrivter af ntiturhistorle Selskabet, Kj0benhavn, vol. 3, pp. 46-54, pi. 5, figs. 1-11. 

 »Suppl. Bncyc. Brit., vol. 1, p. 406. 



