176 



caudal stylets situated close together; they are very small, and each of them is provided 

 with a pair of fairly long setae. 



MALE. Unknown. 



OVISACS. They resemble those of the former species. The ovisac represented 

 in fig. 2 c is 1-7 mm. long and 1-4 mm. broad. In one female Avere found eleven ovisacs. 



LARVA. Specimens wliich are full-grown though they have been pulled out of an 

 ovisac, resemble those of the former species to such a degree that I have not been able to 

 find a single distinguishing mark which appeared to me vaUd. 



POST-LARVAL DEVELOPMENT. Unknown. 



HABITAT. The branchial cavity of Hippohjte polaris (Sab.) and Hipp. Gaimardii 

 M.-Edw. from the Kara Sea. My material from this locality is as follows: in a female 

 without eggs of Hipp, polaris appeared beneath a large swelling on the left side of the 

 carapace, the above-mentioned gigantic specimen. In an adult male of Hipp. Gaimardii occurred 

 under a swelling on the right side of the carapace : a female (represented in fig. 2 a) and 

 eleven ovisacs (containing eggs, Nauplii and fully developed larvae respectively); besides an 

 adult male and a nuicli smaller, exceedingly young female of Gyge Hippolytes (Kr.); the 

 two foremost gills of the host, pertaining to the trunk-legs, had disappeared, the three hind- 

 most ones were well preserved; under the apparently sound left-hand side of the carapace 

 of the host, one male Gyge was discovered. In another somewhat smaller male of Hipp. 

 Gaimardii occurred in the front part of the left branchial cavity three rather small females, 

 placed obli(iuely in a longitudinal row, in the right branchial cavity five similar females, 

 three of them far to the front. All the parasites were of sub-equal size and about 1(3 to 

 17 mm. in length; the gills were somewhat crumpled, and the carapace showed small cavities 

 on its inner side in the parts which covered most of the parasites, though its outside did 

 not as yet show any real swellings. No Epicaridea were discovered. 



Tills species has been found besides at the West-coast of Greenland : in the Karajak- 

 Fjord, district Umanak (on ab. lat. 70^/3" N.), by Dr. E. Vanhoffen. Tlus naturalist having 

 informed me in a letter that he had found Choniostoma, I asked him to lend me his material, 

 and he kindly placed it at my disposal, as well as his own particulars about it. He pos- 

 sessed in all four females; two of these belonged to Ch. Hansenii, he had found them free 

 in a bow-net, and he writes about them: » .... die ich lose fand, und die aus Krebsen 

 stammen miissen, welche in meiner Reuse sich hauteten oder verzehrt wurden« ; about the 

 others he writes: »Ein drittes Exemplar wurde in H. Gaimardii ..... ein viertes in H. po- 

 laris .... gefunden« ; one of these was Ch. Hansenii, but the other was »zur Halfte auf- 

 geschnitten* , so that I could not determine it, and I do not know in what species 

 of host the specimen had been found. So at least three of the four parasites per- 

 tained to this species, moreover, it seems very probable that it lives in both species of 

 Hippolyte. 



