34 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. r>3. 



10. Cepbalothorax with three simple chitin horns, two lateral, one dorsal ; 



neck much longer than the trunk, not reflexed ; abdomen half the length 

 of the genital segment, witliout processes Trifvr, new genus, p. 101. 



11. Abdomen with a row of feathery processes along either side; cephalotho- 



rax with numerous frontal processes and two or three horns, chitinous 



and usually simple FcnncUa Oken, ISIG, p. 105. 



11. Abdomen twisted spirally and covered with papilliforra villi; neck with 

 small excrescences attached by threads; no horns or frontal processes. 



PcycsinxiUus Kr0yer, ISGo, p. V2G, 



Remarks. — At first the genus Lernaca was the only one in the en- 

 tire group of parasitic copepods, and everything that was parasitic 

 and that seemed likely to be, or even to become, a copepod was placed 

 in this genus by the early investigators. One after another of theso 

 species have been removed and made the types of new genera, until 

 all that are left are those included in the present paper. lUit even 

 after they began to separate new genera investigators still placed 

 them all with Lernaea in the family Lernaeidae, which thus became 

 the final dumping ground for everything that was bizarre in form 

 and that could not be located elsewhere. Many of these genera have 

 already been removed and correctly located elsewhere, and it is pro- 

 posed now to remove all the others that do not show sufficient rela- 

 tionship in morphology and development. Accordingly the live 

 genera, Sphyrion^ Sti'abax^ Trypaphylum^ Opimia, and Rchellula^ 

 which have heretofore been included in the Lernaeidae, must be 

 dropped for the following reasons: The adult females of these genera 

 haA'e processes at the posterior end of the genital segment in addi- 

 tion to the ^g^ strings, from a single pair (Opimia) up to large 

 bunches {Sphyrion) ; the second antennae are neither dorsal nor 

 chelate; there are no swimming legs or anal laminae, and the female 

 carries a pigmy male attached to the posterior end of her body. Tiiis 

 last proves at once that the life history is entirely different from 

 tluit here set forth for the Lernaeidae. These genera will be taken 

 lip in a future paper. 



The genus Ive which was provisionally placed in the Lernaeidae 

 by its founder, Mayer (1879), can not possibly be left there, since it 

 is not a fixed parasite at all and the two sexes are found together 

 moving about freely, with the male 5 mm. in length, or half the size 

 of the female. 



The genus Lernaea presents so many differences from the other 

 genera that it might seem a question whether it ought to be in- 

 cluded with them or established in a family by itself. But from the 

 account of that genus already given (see Bibliography under Wilson) 

 it will be found that the resemblances far overbalance the dill'er- 

 ences, especially in the matter of the peculiar life history, and the 

 genus is accordingly retained in the present family. 



