ARCA. 95 
the description, although tolerably ample, being at variance 
with the only recognisable figure of the two quoted (Gualtier, 
C, and Rumphius) does not adequately define the object 
intended. 
The assigned localities, being merely taken from those 
attached to the misquoted figures of Lister and Adanson, are 
not to be depended upon. 
Arca sentlis. 
This very pecular-looking Ark was easily recognised, at an 
early period, from its synonymy and description. A marked 
specimen of it (Adanson, Senegal, pl. 18, f. 5) is still present in 
the Linnean cabinet. It is the Arca senilis of modern writers 
(Reeve, &c.) hkewise, and is further illustrated, in the revised 
copy of the ‘Systema,’ by a reference to “ List. t. 238.” 
Avea granosa, 
This species first appeared in the tenth edition of the 
‘Systema, with references to figures in Columna, Bonanni, 
Gualtier, and Argenville. The two former engravings are so 
ill executed as to be almost irrecognisable. The first repre- 
sents a crowdedly grooved fossil; the second a mere interior, 
which, intended possibly for A. diluvit (judging, at least, from 
the Italian locality) was probably only quoted from being cited 
for this species by Gualtier. Both the latter are decidedly 
meant for the Arca granosa of modern conchology, of which the 
characters are in accordance with the postulates of the diag- 
nosis. ‘The erroneous locality was derived from the statement 
of Bonanni, the reference to whose work is correctly expunged 
in the copy of the younger Linné, who has substituted “ List. 
t. 242, f. 79.” The Arca granosa (Chemn. Conch. Cab. vol. vii. 
pl. 56, f. 557) is still present in the collection (as indicated in 
the list) and alone of the shells therein contained agrees with 
the combined pictorial and descriptive definition. 
Although Gualtier and Argenville alone are cited in the 
