British species of the genus Lagciia. 11 
followed will not suit the views of many of my conchological 
friends, who would have preferred my multiplying the number of 
species to a far greater degree than I could approve. I have 
however endeavoured to compromise the matter with them by 
giving names to what I consider to be merely varieties, but which 
some would regard as good species. Those who prefer the latter 
view can act upon it if they choose, by adopting these names as 
specific ones. This capacity for variation is probably a charac- 
teristic of very many of the lowest forms of animal and vegetable 
organizations, and is a source from which more or less of diffi- 
culty will always arise in attempting to classify objects so small 
in their dimensions and so obscure in their nature. In the pre- 
sent case it would scarcely be a difficult task to exhibit every in- 
termediate form between Lagena Icevis. var. Amphora to L. striata 
and L. suhstriata, rendering it possible that they may be all va- 
rieties of one species. 
The Lagence are usually found in dried sea-sand, free and de- 
tached, thoTigh Prof. MacGillivray observed Lagena Icevis to be 
adherent to Fuci and the byssus of a Modiola ; and amongst the 
branches of an Antennularia sent to me from Falmouth by Mr. 
Jeffreys were numbers of the Entosolenia marginata along with 
Rosalina globularis and Polystomella crispa. 
In dividing the objects comprehended by Dr. Fleming, in De 
MontforPs genus Lagenula, into two groups, I have retained for 
the first of these WalkePs term Lagena. Though the latter did 
not make them into a new genus, separate from Berpula, yet he 
distinctly indicated the necessity for a division, pointing out cer- 
tain well-marked forms, and giving them a distinguishing name. 
In this he accomplished more than was subsequently effected by 
De Montfort ; hence, in raising them to the rank of a genus, pri- 
ority gives his name of Lagena the right to a preference before 
that of Lagenula. The adoption of the latter by English concho- 
logists was owing to its introduction by Dr. Fleming into his 
^ British Animals,^ where he employed it, I understand, because 
of its being more euphonious than Lagena, notwithstanding 
that, as has been already mentioned, he had previously adopted 
WalkePs very expressive term for the genus in the ^ Edinb. Ency- 
clopaedia^ (vol. vii. pi. I.p. 68, art. Conch. 1815). A slight im- 
provement in the sound, or even expressiveness of a name, does 
not justify its displacing an older one, and hence throughout 
this memoir I have retained that of Lagena in preference to 
Lagenula. 
Genus Lagena, Flem. Edin. Enc. 
Serpula {Lagena), Walker. Serpula, Turton. Vermicuhnn, Mon- 
