OSTREA. 101 
author, and the specimens, as I have reason to believe, were 
introduced subsequently to the arrival of the collection in 
England. 
OSTREA. 
It was the design of Linneeus, as we learn by his manuscript, 
to remove the four last members of the Ostrea from the rest, 
and to constitute for them a new and distinct genus. This 
group, equivalent to the Lamarckian Perna (not that of Retzius), 
is thus characterised and thus named in a copy of the 
‘Systema’ which belonged to the younger Linné: “ Testa 
compressa, valvuli equaliter plani, cardo cicatricibus pluribus 
transversis. Absque dentibus, sed divisa foveis transver- 
salibus.” The portion in italics was in a different hand- 
writing from the rest. 
The original markings upon the Ostree of the Linnean 
cabinet have been erased, and another set, to which I can 
discover no key (the numerals do not correspond with those in 
the arrangement of species suggested by the younger Linné) 
has been substituted. The collection, therefore, scarcely aids 
us at all in working out the members of this genus, a circum- 
stance the more to be deplored from the acknowledged diffi- 
culty with regard to most of the Pectens, whose sculpture being 
wholly omitted, or very inadequately delineated by the older 
engravers, has rendered the synonymy of less value, from the 
impossibility of recognising what species the figures were 
designed for. 
In certain cases the names are written upon the specimens 
with a pencil (e. g. upon radula and ziczac, the latter as “ vix 
Linnei”’), but the handwriting cannot be confused with that of 
Linneus, and was probably that of Sir J. Smith, whose habit, 
with the Linnean herbarium, at least, was to use a pencil 
