CABIROPSID^— CEYPTONISCID^ 401 



Gahirops lernoeodiscoides, Kossmann (1872), was foimd 

 in the brood-cavity ofa,Bopi/rus from the Philippines. To 

 this genus Giard and Bonnier approximate Gryptothiria{?) 

 marsupialisj Sars, reported to ha parasitic on two species, 

 Marycope cornuta and Ilyaracluia lonjicornis. The female 

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

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

 with an ovate oral area, and no appendages. 



Podascon, Giard and Bonnier, 1889. ' All the b3dy 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 person and united 

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

 an opening for the passage of water.' 



Fodascon 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 LeucotJwe 

 spinicarpcb in the Ascidian Fliallusia gelatinosa, may in the 

 opinion of MM. Giard and Bonnier prove to belong to 

 the Cabiropsidse. A Cryptoniscus-form found by myself 

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

 Arctic regions, closely agrees with the Ilemioniscus halani 

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



FamUij 5. — Gnjptoniscidce. 



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 MuUer 

 ingeniously suggests that in becoming parasitic they took 

 with them their own parasites, the Cryptoniscidae. Giard 

 and Bonnier further suggest that the Entoniscid^e 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. 



