ABT. 5. NORTH AMERICAN PARASITIC COPEPODS WILSON. 3 



Eisso's type specimens and found them the same as his own, yet Risso 

 described them again in 1826 under the name Otrophesia imhricata* 

 and even quoted Leach as the authority for his new generic name. 

 A careful examination of the three descriptions and their accompany- 

 ing figures makes it erident that they were all dealing with the same 

 species. But it is not a species of Caligus, and hence Leach's generic 

 name is valid with the specific name given by Abildgaard, and the 

 species becomes Anthosoma crassum. It was retained, however, in 

 the genus Caligus by Lamark, who even made separate species of 

 imhricatus and smithii. All other authors since Leach have adopted 

 his genus, although there has been considerable division of opinion 

 over the three specific names. 



Similarly Abildgaard's second species, oblongus^ was made the 

 type of a new genus by Hermann in his " Memoire Apterologique " in 

 1804. Like Leach, he seems not to have known of Abildgaard's de- 

 scription and figures, for he named his new genus type DiGhelesthiurn 

 stianonis. This genus name was adopted by Oken, 1816, Desmarest, 

 1825, and Nordmann, 1832, but was changed to Dichelestium by 

 Latreille, 1817, and all other subsequent authors except M. J. Rath- 

 bun, 1905, and Norman and T. Scott. 1906, who retained Hermann's 

 original spelling. To none of them, however, except White, 1850, 

 and the last two just mentioned, not even to those who claimed that 

 Abildgaard's species and Hermann's were identical, did it occur that 

 the species name given by the former must take precedence over that 

 of the latter (see p. 86). 



To these two original genera others have been added from time to 

 time, as indicated in the kej'^ upon page 20. Of these Blainville 

 added Lernanthropus in 1822, Nordmann contributed Lamproglena 

 in 1832 and Donusa and Norion in 1864, P. J. van Beneden con- 

 tributed Ergasilina in 1851, Eudactylina and Kr0yer'ia in 1853, and 

 C oiigericola in 1854. He was apparently unaware that this last 

 genus was identical with Milne Edwards's Gycnus^ since he makes 

 no mention of the latter. But since the name Cycnus had been pre- 

 occupied (see p. 67) Beneden's name becomes valid. 



The remaining genera have come at scattered intervals, most of 

 them within the present century. The descriptions and figures have 

 been uniformly good, so tha.t now we have reliable data upon their 

 general form and habits. But there has been much less information 

 with reference to their internal morphology and their life history. 



Heider in 1879 published a monograph entitled " Die Gattung Ler- 

 nanthropus," in which he gave an excellent account of the internal 

 anatomy, and included also the minute histology of the various tis- 

 sues, but this is the only genus to be so treated, and in reference to 



* Hist. Nat. Paris, vol. 5, p. 136. 



