140 On two Genera of Semiparasitic Polyzoa. 
The diagnosis given above of r T. flava, however, as drawn up 
by Sars from Dalyell’s figure and description, by no means cor¬ 
rectly represents the species found by me at Oban, and which, 
I cannot doubt, is that indicated by Dalyell, more especially 
as both were found affecting Sacculina carcini. It appears 
to me that Sars has laid too much stress on the comparative 
length of the pedicel as constituting a specific character. It 
will be seen that whereas in T. Bceckii the pedicel is three or 
four times as long as the body of the animal, in T. Korenii 
it is said to be about equal in length, while in T. flava it is 
u much shorter than ” the zooecium. Now I find very wide 
difference in the length of the pedicel in the animals consti¬ 
tuting the group which I found at Oban : in some full-grown 
specimens the pedicel is shorter than the zooecium ; in others 
it is slightly longer; in others, again, it is two or three times as 
long. Specific characters, therefore, derived from the length 
of the pedicel seem in a very great measure to break down. 
The zooecia closely correspond with those figured by Sars of 
T. Korenii : the general form is the same; the position of the 
frenaculum agrees; and there is the same angle at the lower 
extremity of the ventral concave and more membranous area. 
Having only found my specimens after they had been pre¬ 
served in spirits, and the lophophores being in every instance 
strongly retracted, I am unable to speak with accuracy as to 
the number of the tentacles, which Sars states are eighteen in 
Korenii and twenty in flava and Bceckii. The budding young 
agree with Sars’s figures 6, 7, 8, representing this state 
in Korenii ; and the animals are connected by a creeping 
stolon. 
Bearing in mind, then, that reliance cannot be placed on 
minute details in the drawings of DalyeJl, I am constrained 
to come to the conclusion that no valid grounds exist (as far, 
at any rate, as we as yet know) by which to distinguish the 
Scotch species, which affects Sacculina carcini and is the 
type of Dalyell’s Triticella flava from the Norwegian form 
found by Sars on Calocaris Macandrewi , and that the latter 
must be regarded as a synonym—further, that great latitude 
must be allowed with respect to the length of the pedicels, 
which in T.flava show great variation, and are often not only 
as long as described in Korenii , but show a great approach 
to the very long supports of T. Bceckii. The higher posi¬ 
tion of the frenaculum in T. Bceckii appears to be its chief 
character. 
