306 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.39. 



for he states in so many words that the species was "hitherto unde- 

 scribed" (hidtil ubeskrevne Art). 



Pagenstecher's generic distinction seems to be a vahd one (see 

 p. 349), and hence this species does not belong to the genus Ergasilus 

 at all. 



The other species for which the male is given, E. sieholdU Nord- 

 mann, is of course vahd, since it is the type of the genus. 



But here Kroyer has made the same mistake as in several other 

 instances of designating a young female without egg strings as a 

 male. The true male differs from the female in the presence of well- 

 developed second maxillipeds, and Kroyer's figures distinctly show 

 that these are lacking in the specimen which he calls a male. 



Furthermore, it will be seen from the systematic discussion given 

 on page 367 that three of the species which he assigns to the genus 

 Bomolochus really belong to other genera. 



His contribution, therefore, serves chiefly as a source of material 

 for subsequent correction. 



In the next year (1864) Claus gave a detailed account of two new 

 species of Bomolochus {solese and cornutus) and a new and closely 

 allied genus which he called Eucanthus, with the species E. halistse. 

 He discovered also and described the true males of both these genera. 

 And finally he gave a systematic review of the genus Bomolochus and 

 its relatives, bringing out clearly the position of the family and its 

 relation to both the free-swimming and parasitic forms. With this 

 end in view he made a thorough revision of the mouth parts, locating 

 and naming the different appendages around the mouth, which Bur- 

 meister had not understood and which Thorell and Kroyer had inter- 

 preted incorrectly. He concluded that the mouth parts in the Erga- 

 silidae are half-way between those of the Corycaeida? and the Chon- 

 dracanthidse. In particular he contended that mandibles are present 

 in all the Ergasilidse, and that, therefore, they could not be included 

 in Thorell's group of Poecilostoma. But while thus destroying in a 

 measure the classification Thorell had made, he offered no substitute 

 in its place. 



Even in the fifth edition of his Lehrbuch der Zoologie (1891) he 

 makes no mention of a single genus belonging to the Ergasilidffi or the 

 Dichelestiidaj, nor is there any place for them in the classification of 

 the copepods which he gives. 



In 1870 Claparede published a Note sur les Crustaces copepodes 

 parasites des Annelides et Description du SaMlijMlus sarsii, in 

 which he gave his views upon these troublesome semiparasites. He 

 declared that Claus's statement in regard to the presence of mandi- 

 bles is correct. But he believed that when the details of the mouth- 

 parts have been fully investigated, it will be found that in Licho- 

 molgus and other genera, as well as in his genus of Sabelliphilus, the 



