Lafotidæ and Campanulinidæ. 
The definitions and the relationships of these two old families 
have recently been discussed by Broch (1912a)and Levinsen (1913). 
Levinsen distinguishes the two families from each other exclusively 
by the presence or absence of an operculum, thus placing the genus 
Toichopoma among the Campanulinidæ; in this respect he is followed 
by the late Linko (1912). Broch is of the opinion, that the two 
groups are so nearly related, that they cannot be maintained as 
separate families; he unites them within the one family Lafoéidæ, 
but still keeps them from one another as subfamilies, Grammariinæ 
and Campanulininæ. The transition between the two subfamilies is 
realized by the range: Lafoéa — Toichopoma — Stegopoma; the 
limit has been drawn between the two last named genera, thus 
Toichopoma being placed among the Grammariinæ as nearly related 
to Lafoéa. 
The result of my studies on the genera of hydroids usually 
referred to the groups Lafoéidæ and Campanulinidæ, is that the 
last mentioned family (or subfamily) cannot be maintained. It will 
be most practical to begin the discussion of the matter with some 
remarks on the position of the genus Tnichopoma. In 1892 Levin- 
sen called attention to the great likeness of Toichopoma obliquum 
to Lafoza fruticosa, from which "it can hardly be distinguished 
except when highly magnified" (1. c. p. 178), but though he sepa- 
rated it from Calycella as a proper genus Toichopoma he let it 
remain among the Campanulinidæ because it was provided with an 
operculum. .Broch (1909) conjecturally placed it near Lafoéa, re- 
garding it as forming the transition to the operculate Campanu- 
linidæ. In my paper 1911 I described the gonosome which is a 
typical coppinia very much like that of Lafoéa fruticosa. In spite 
of this fact Levinsen again (1913) places Toichopoma together 
with the other operculate genera in the family Campanulinidæ, se- 
parated from the Lofoéidæ by the mere presence of an operculum, 
though he is of the opinion that the different genera of Campanu- 
linidæ with their different types of operculum have separated inde- 
