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 Gordiide 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 Nectonemide. But whatever 
may be the final decision in regard to the rank of the Gordiide, 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 Gordiidz 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. 
