HOMOLOGY OF THE RECENT PH YLLOC ARI D A. 



In the following pages I proisose to discuss more in detail the homologies of the 

 several parts in the Nebaliidte, as compared with those in other recent Crustacea. As 

 has been indicated at the beginning of this Report, my view as to the relationship of 

 the genus Nehalia to other known Crustacea somewhat differs from that set forth by 

 most other naturalists, and the examination of the two related new generic tyj^es pro- 

 cured by the Challenger Expedition, and described above, has confirmed me still more in 

 the opinion at first adopted from a thorough investigation of our common northern form, 

 Nehalia bipes, Fabricius. 



It is certainly astonishing that the great resemblance of Nehalia to certain Copepoda, 



Fio. 2. — Diosaccus tenuicc/mis (Cltius), mafe. 



has escaped the attention of most naturalists who have subjected this genus to a closer 

 examination, whereas the much more remote affinity to the Podophthalmia has always 

 been dwelt upon, and even Professor Claus, to whom we are, as is well known, indebted 

 for an admirable work on the free living Copepoda, does not seem to have been aware 

 of this unmistakable resemblance ; I tliink it may be readily found by a closer com- 

 parison, that the affinity of Nehalia to the Copepoda is in fact much greater than to the 

 Podophthalmia, both as regards the external appearance and the structure of the several 

 appendages. In some other important points it exhibits, on the other hand, an evident 

 agreement with the Phyllopoda, and for that reason it ought to be, in my judgment, 



