PARASITA. 



241 



spennatoplioi'es, has attained full development. Tins free-swimming copulatory 



Cyclops stage is the last 



stage 



of the male, the fertilised female, however, 

 in which she undergoes marked trans- 



seeks a new host (one of the Gudidae), 

 formation of the body 

 (Fig. 114 C and D). 

 The genital segment, 

 which has enlarged 

 for the development 

 of the eggs, is now a 

 large doubly -curved 

 portion of tlie body, 

 the small abdomen, 

 with its truncated 

 furcal appendages, 

 forming its termina- 

 tion. The cephalo- 

 thorax is changed by 

 the addition of three 

 horns which function 

 as barbed hooks, 

 carrying at their 

 points fork -like out- 

 growths. During 

 these transforma- 

 tions, the limbs are all 

 retained, but are to a 

 certain extent trans- 

 formed 1 ly strong 

 chitinisation. 



The remarkable 

 form Sjjliacronella 

 Lcuckartu, which is 

 parasitic in the brood- 

 cavity of Amphitlioe, 

 is connected with 

 Lernaea by its 

 metamorphosis. 

 Salkxsky (No. 80) 

 found in Sphaeronella 

 an extremely degene- 

 rate pupal stage fol- 

 lowing the first free- 

 swimming Cyclops 

 stage. Neither seg- 

 mentation nor limbs 

 were recognisable in 

 the sac-like body 

 which was attached 



by a larval adhering apparatus to the epimeral plates of tlie host, 

 led, through gradual transitionary stages, to the adult form. 



The metamorphosis of the Lernaeopodidac is best known through the works 



Fig. 114. — Sexually mature stage of Lernaea hranehioMs (after 

 Claus). a, male. B, female at the copulatory stage. C and 

 D, later conditiou of the female transformed by parasiti.sm, 

 slightly magnified, o', first, a", second antenna ; }l-S"^t first 

 four pairs of thoracic limbs ; g, opening of the receptaculum 

 seminis ; mxj, maxillipede ; oc, eye ; sp, spermatophoral sac ; t, 

 left testis. 



This stage 



R 



