II. 



The pelagic Ctenophora of the Northern Atlantic. 



The species mentioned in this part of the report have, most of them, been the object of 

 repeated descriptions, a very extensive literature existing about them. There is no reason to enter in a 

 more detailed manner upon these forms in general; however, I am able to give some additional infor- 

 mation, which may be found not without value. As for the literature it has been thought unneces- 

 sary to quote all the references; they have been very carefully collected by Romer and Moser, to 

 whose works I may refer. Only the more important references are given. 



The species dealt with in this part are: 



Mertensia ovum (Fabricius). 

 Pleurobrachia pileus (O. Fr. Miiller). 



— crinita Moser. 



Bolina infundibulum (O. Fr. Miiller). 

 Bcroe cucumis Fabricius. 



Besides, notes are given on some few other species, which have been recorded as occurring 

 in the Northern Atlantic, viz. Hormiphora plumosa (Sars), Lesueuria hyboptera A. Ag., Cestus veneris Les. 

 and Beroe Forskalii Chun. 



The species hitherto recorded only from the Atlantic Coasts of North America are not dealt 

 with, unless there are synonymical reasons for mentioning them. 



1. Mertensia ovum (Fabricius). 



Beroe ovum. O. Fabricius. Fauna Groenlandica. 1780. p. 362. 



— compressa. H. Mertens. Beobach. u. Unters. iiber die beroeartigen Akalephen. Mem. Acad. Imp. 



St. Petersbourg. 6. Ser. II. 1833. p. 525. Taf. 9. 



— octoptera. — Ibid. p. 528. Taf. 10. 



Mertensia ovum Morch. A. Agassiz. North American Acalephse. 111. Catal. Mus. Comp. Zool. II. 



1865. p. 26. 



— — Fabr. E. Vanhoffen. Die gronlandischen Ctenophoren. Bibl. zool. VIII. 1895. p. 17. 



— — — — Ctenophoren. Nordisches Plankton. XI. 1903. p. 2. 



