MUSEUM OF COMPARATIVE ZOOLOGY. 187 



embryonic development as well as from the life history and structure 

 of the larva, will make this matter clearer. 



Nearly all writers agree in placing the Gordiidse in an isolated posi- 

 tion under the Nematodes. ' If, according to the proposal of some, this 

 family be raised to the dignity of a separate order, then there is no 

 doubt in my mind of the right of Nectonema to a position in that order 

 as the representative of a new family, the Nectonemidae. But whatever 

 may be the final decision in regard to the rank of the Gordiidee, this 

 new family must take its position near that group. That the relation- 

 ship is close enough to warrant the inclusion of the genus Nectonema 

 in the family of the Gordiidse is hardly possible, but a final opinion on 

 this point can be given only in the light of more complete knowledge, 

 especially on the points just enumerated. It is my intention to investi- 

 gate the subject further, and to follow if possible the life history of this 

 most interesting form. 



Cambridge, March 25, 1892. 



