267. 
not necessarily give their names to the species which the include: 
Thus they discourage the growth of synonyms, offer no awkward 
bars to the free passage of any species from one group to nearer 
relatives, and at the same time lessén the confusion. which the 
present unsettled state of" opinion regarding thé relationships of 
existing species tends to produce.” "When the groups are to. take 
the placés of genera, one should believe that the generic. names 
must be quite superfluous except ås synonyms, and I am at a loss 
to understand in what manner this retention of them måy be able 
to diminish the growth of synonyms or to lessen confusion of any 
kind, as I am much more inclined to think that this method would 
have quite the opposite result. 
In the year 1904 Professor C. C. Nutting., Iowa, published 
a most valuable work on the American Sertulariidae, in which as 
aå' result of his systematic investigations into this family he sets 
forth the assertion that: the characters taken from the opereulum - 
and the hydrothecal margin are insufficient in themselves to furnish 
a. base for the classification: of the Sertulariidae"), though he 
»thinks them most important aids "in defining certain genera” and, 
besides, he quotes parts of an unpublished manuscript on the 
structure of. the operculum written by Mr. J. H. Paarman?), 
according to which the representation the present author has given 
of the operculum in the Sertulariidae is incorrect. I am first to 
treat the latter point, and the following representation of the 
results to which the two authors have arrived uk refers to Ser- 
tularia pumila. 
According to the named authors the plrothosi margin .is 
provided with two lateral teeth, between which there are stretched 
two quite homologous membranes of unequal size, the: abcauline 
being considerably larger than the adcauline one. … They form 
together' the side-walls of an .A-tent, the front: and rear of "the 
tent being closéd by the two opposite hydrothecal teeth, and there- 
1) 44, p. 41. 
2) 44, pp. 20, 40. 
