CABIROPSIDJE CRYPTONISCIDJE 401 



Cabirops lernceodiscoides, Kossmaiin (1872), was found 

 in the brood-cavity of a Bopyrus from the Philippines. To 

 this genus Giard and Bonnier approximate Cryptothiria (?) 

 marsupialis, Sars, reported to be parasitic on two species, 

 Euryeope cornuta and Hyarachna lonyicornis. The female 

 only of this parasite is known. It is a simple pellucid 

 broadly bilobed sack, narrowed in front, filled with esrgs, 

 with an ovate oral area, and no appendages. 



Podascon, Giard and Bonnier, 1889. ' All the bxly of 

 the female is, so to speak, transformed into a vast incuba- 

 tory chamber, enclosed by two lateral plates extending from 

 the first to the fifth segment of the peragon and united 

 along the median line so as merely to leave at either end 

 an opening for the passage of water.' 



Podascon Dellavallei, Giard and Bonnier, 1889, on the 

 Amphipod Ampelisca diadema (Costa). When first de- 

 scribed, this was the only known instance of an Isopod 

 parasitic on an Amphipod. New forms have since been 

 found by M. Chevreux on three other species of Ampelisca. 

 Also a Cryptoniscus-form found by Gourret on Leucothoe 

 spiniccwrpa in the Asciclian Phallusia gelatinosa, may in the 

 opinion of MM. Giard and Bonnier prove to belong to 

 the Cabiropsidte. A Cryptoniscus-form found by myself 

 among the eggs of an Onisimus plautus (Kroyer) from the 

 Arctic regions, closely agrees with the Hemioniscus balani 

 of Buchholz, which is a member of the next family. 



Family 5. Cryptoniscidce. 



They are parasitic on Cirripedes, chiefly on the para- 

 sitic Rhizocephala. It is reasonable to believe that the 

 Rhizocephala did not begin their existence as parasites, 

 but descended from independent Cirripedes. Fritz Miiller 

 ingeniously suggests that in becoming parasitic they took 

 with them their own parasites, the Cryptoniscidte, Giard 

 and Bonnier further suggest that the Entoniscidse and 

 Bopyridae were introduced to the higher Crustacea by an- 

 cestors parasitic on Rhizocephala, and that in course of 

 time they found their advantage in exchanging an indirect 

 for a direct parasitism. 



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