18 . C. McLEAN FRASEE 



SYSTEMATIC DISCUSSION 



In the nomenclature used in this paper no new departures have 

 been made from that in most general use by other authors. Other 

 things being equal, that used by authors who have done the great- 

 est amount of work in the field, has been followed. 'Tis true that 

 sometimes there is no little disagreement among these on certain 

 points, but in all cases a position has been adopted such that any- 

 one who is familiar with Hydroid Literature, will be able to trace 

 with ease the relation of any species, and that is the chief use for 

 nomenclature. 



In case any particular author is folloM^ed in any family or 

 group, it is indicated in the special discussion at the point where 

 the family or group is taken up. Where no author is followed 

 in entirety, the characteristics of the family or group are given 

 as used. Except in special cases no authors' names are given ex- 

 cept in connection with the species. 



1 have made no endeavor to indicate all the changes in syn- 

 onymy, as that is necessary only in monographic work. I have 

 tried in every case to give the original binomial designation with 

 its reference and at least the majority of references made by 

 authors who have dealt with the Hydroids of the "West Coast. 

 Further references can readily be obtained from the works of 

 such authors as Nutting, Broch and Jaderholm. 



GYMNOBLASTEA 



In taking up the gymnoblastic hydroids, I have followed All- 

 man's classification- almost entirely, at least as far as the 

 Families are concerned. For that reason I shall not give the 

 characters of each family, simply taking these given by Allman 

 as the basis. I do this because, while I think it makes very little 

 difference how the classification is made as long as the species 

 referred to, is made evident, there certainly is nothing gained in 

 cleai-ness by grouping as much as some authors do, even where 

 intergrading takes place, as it is always liable to do. Allman 

 has not gone so far in the other direction as to make confusion 

 by division into smaller groups. In any case his classification 



2 Monograph of Gymnoblastic Hydroids, Eay Society, 1871. 



