118 SPECIES OF THE SYSTEMA. 
two shells. The description of its hinge demonstrates that it 
belongs to the genus Perna (as now understood), and the 
“colore ligni putridi seu ferruginea” is very expressive of the 
colouring of P. sulcata. Of this species a specimen, which is 
preserved in the Linnean cabinet, is here portrayed (pl. 2, f. 7), 
not as positively the shell intended by our author (with whose 
description, however, it agrees), but partly because I know of 
no characteristic delineation of it, partly because it is highly 
probable that such was really the object he wished to define. 
Ostrea (Soquonron, 
Linneus had not this Perna, over whose name he has 
written “gen. noy.” in his revised copy (the proposed thir- 
teenth edition) of the ‘Systema.’ The language of the ‘ Mu- 
seum Ulrice’ respecting it leaves no doubt of its identity with 
the P. isognomon (Chemn. Conch. Cab. vol. vii. pl. 59, f. 584) 
of authors. The synonymy is essentially correct, but includes 
those forms which Lamarck has separated from isognomon as 
P. femoralis and canina. In the reference to Rumphius in the 
twelfth edition the 1 is a typographical error for I., which stood 
there both in the preceding edition and in the ‘Museum 
Ulrice.’ 
Ostrea ephtpptiunur. 
Linneus has not inserted the name of this species in the 
list of the shells possessed by himself. Although the figure in 
Rumphius is irrecognisable (it exhibited, however, the required 
form), the description in the ‘Museum Ulrice’ has enabled 
conchologists to identify this Perna with facility (Chemn. 
Conch. Cab. vol. vii. pl. 58, f. 576). Even the brief definition 
of it in the ‘Systema’ would have sufficed for its determination, 
since the account of its hinge proved it was a Perna, and the 
expressions “ orbiculata,” “‘rudis fusca” were formally applic- 
able to but one known species of that genus. “Gen. noy.” has 
been written by Linneus, in his own copy, over the name 
