596 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



go and clings to the body of the female for the rest of his hfe. Sub- 

 sequent to attachment the changes which take place in the copepod 

 are chiefly concerned with the development of the reproductive 

 organs. In the fixed female the legs, the segmentation of the body, 

 and frequently the anal laminae disappear. At the same time the 

 trunk or so-called genital segment increases through the develop- 

 ment of the convolutions of the oviducts and becomes relatively as 

 well as actually much larger than before, and finally the external 

 egg sacks are formed, which may be regarded as the completion of 

 the life cycle. 



The male does not increase much in size, but remains a pygmy; he 

 usually loses the two pairs of swimming legs, but retains, in part 

 at least, the body segmentation. The maturing of the spermato- 

 phores and their subsequent attachment to the genital process of 

 the female marks the completion of his hfe cycle, and he does not 

 probably hve very long afterwards. 



SYSTEMATIC. 



Historical. — In the first edition (1735) of his Systema Naturae 

 Linnaeus placed aU the crustaceans among the wingless insects under 

 three genera. It is very doubtful if any member of the present 

 family was included in this first edition. But later in the second 

 edition of the Fauna Suecica (1761) he described Lernaea salmonea, 

 which is really a Lernaeopod and probably the oldest member of the 

 family, and which he located among the moUusks. 



Having thus begun under the genus Lernaea, the present family 

 was for a long time included with the Lernaeidae. On account of 

 their degenerate form they were not placed with the Crustacea by 

 any of the earher zoologists. Lamarck, after locating them among 

 the moUusks (1801) and the anneUds (1809) went so far as to create 

 a separate group to receive them (1812) which he called the Epizoaria 

 and placed between the worms and the insects. In his Handbuches 

 der wirbeUosen Thiere (1816) he writes that he had found Lerneans 

 which showed a transition from insects to worms so that the Epizoaria 

 could be regarded only as a provisional or temporary class. 



Bosc, also following Linnaeus, placed them among the mollusks 

 (Historia Vermium, n. d.), but contended that they were closely 

 related to the intestinal worms. Oken, in his Lehrbuch der Natur- 

 geschichte (1815-16), included some of the Lernaeopodidae in two 

 different places. First he placed among the worms (pp. 182-184), 

 between EcTiinorhynchus and Hamularia, the genera Philline, ScJiis- 

 turus, and Lernaea. Second as a separate group, the Armwiirmer 

 (pp. 357-359), between Asterias and Gordius, he placed not only 

 Axine, Clavella, Pennella, and Lernaea, but also DichelestJiium, Caligus, 



