280 
The author furtker adds 1 ): “The features here noted in Thu - 
jaria polymorpha bring to mind a phenomenon not unknown in the 
vegetable kingdom; as in the case of certain ephiphytical orchids, 
in which flowers whose differences of form are such as to have 
caused them to be regarded as characterizing so many distinet 
genera, are nevertheless found associated in one and the same 
plant/’ I do not think, however, that the last named case has 
induced any botanist to prefer systematic characters taken from the 
form of the inflorescences to those presented by the individual flowers. 
Hydrallmania (Hincks) Nutting. 
I shall later mention this genus to which Prof. Nutting 
besides H. falcata refers two other species, H. disians Nutting 
and H. franciscana (Trask). 
Selaginopsis (Allm.) Nutting. 
While Me resch kowsky to this genus refers all Sertulariidæ, 
the hydrothecæ of which are arranged in more than two longitudinal 
series, Allm an excepts such species which may be referred to 
the artificial genera Pericladium Allm. and Dictyocladium Allm. 
According to the above definition Nutting only refers to Sela¬ 
ginopsis such polyserial species, which belong to my genera Thujaria 
and Sertularia, and of the species named in his .work in either 
case S. mirabilis must be referred to Sertularia, but I am not 
sure, whether this may not be the case with some of the others, 
as f. inst. S. ornata and S. pinnata 2 ). 
Among the species which Prof. Nutting in the general part 
of his work selects to show the inconstancy of my systematic cha¬ 
racters is also S. mirabilis, about which he says: “In Selaginopsis 
mirabilis (Verrill) there are two flaps to the operculum, while the 
one-flapped operculum is characteristic of the genus as a whole. 
I do not believe that any one would separate S. mirabilis and S. 
cylindrica (Clark) generically, and yet they differ in this feature 
upon which Le vin sen bases his genera.’’ 
*) 4, p. 148. 
2 ) I have not seen these two species. 
