62 ROYAL SOCIETY OF CANADA 
Senilis. 2. A. subcylindrica transverse rugosa. 
Jonst, Exsang. t. 18, f. 2. Urtica major: minor 
Baster, Subs 3. p. 122. t. 14. f. 2. t. 13. f. 2. Actinia rugis orbicu- 
laribus, proboscidibus multis tenuibus. 
Fn. Suec. 2103 Priapus senilis. 
Strom Sondr. 204 Soekuse. 
Habitat in M. Atlantico super ostreas, rupes. 
Here again the actual description of the species affords no basis 
for an identification, but a study of the synonomy given does yield a 
very pertinent clue. z 
The reference to Jonston is of little consequence; the descriptions 
and figures which that author gives of Actinians are merely compilations 
from earlier writers and the two forms mentioned are illustrated in 
his work by copies of Belon’s figures illustrating the genus Urtica. 
One of the figures represents a contracted, and the other an expanded 
Actinian, and Belon designates them as Urtica contracta and U. explicata 
respectively. In the text he gives no special description of the forms 
figured, merely stating that he had observed several kinds of Urtica, 
some of a red colour and other larger ones, blue with granules arranged 
in a circle. Whether his figures are intended to represent these two 
varieties or whether they merely illustrate two conditions of one and 
the same variety it is impossible to say, and any attempt to refer them 
to a recognized species would be giving definiteness to what is and must 
remain a bare conjecture. 
The reference to Baster is, however, of great consequence. This 
author in his Opuscula subseciva (1762) described three species of Acti- 
nia and illustrated them by figures which are readily recognizable. 
The first species, which he says may be named “ Actinia rugis longitudi- 
nalibus, proboscidibus longis crassis,” is represented in fig. 1, pl. XIII, 
and is evidently that now usually known as Urticina crassicornis; the 
second is named “ Actinia rugis orbicularibus, proboscidibus multis 
tenuibus” and is represented on Pl. XIII, figs. 2, 3, and 4, from which it 
is at once recognizable as the form later described by Ellis as dianthus. 
The third species is represented in fig. 2 of Pl. XIV, and is that to which 
the Linnean name effeta is generally applied. 
In his synonyms of A. senilis Linnæus quotes in full Baster’s name 
for his second species, but unfortunately he cites as illustrations of it 
not only fig. 2 of Baster’s Pl. XIII, but also fig. 2 of Pl. XIV. It hardly 
seems probable that Linnæus should have intended to include under 
one name two forms that are so manifestly different in appearance, and 
the view that the citation of Pl. XIV, fig. 2 in this connection was a 
lapsus penne is practically substantiated by the fact that he quotes the 
