CHAMA. 85 
ville, and perhaps to Rumphius, in whose rude engraving the 
ventral margin has an undulated appearance. 
Chana gigas. 
As our author had asserted his possession of this species, 
search was made, yet in vain, for a marked example. Two 
shells alone, however, in the entire collection will agree with 
the definition of the species; the T’ridacna squamosa (exactly 
Chemn. Conch. Cab. vol. xi. f. 1997, 1998) and a very young 
uncharacteristic individual of a more elongated member of the 
same genus. No one can doubt, from the comprehensive 
synonymy and loose definition of the ‘Systema,’ that Linnzus 
regarded as mere varieties the several T'’ridacne, which natu- 
ralists of the present age justly consider to be entitled to 
a higher rank. ‘To preserve the name, then, it is requisite to 
restrict the Linnean species to that which is described at 
large (and consequently more strictly limited) in the ‘ Museum 
Ulrice.’ The following expressions in that work merit our 
attention—“ decussatim striata, obtuse plicata: plicis quinque 
convexis imbricatis: squamis rotundis fornicatis ascendentibus. 
Margo exterior repandus, parum admodum et obtuse lobatus. 
Color extus flavescens seu rufescens.’—since the five obtusely- 
rounded folds, the reddish or yellowish colouring, the rounded 
and almost erect scales, the coarse decussation, apparent, not 
merely in the hollows, but even, though more delicately so, on 
the ribs themselves, form a combination of characters which is 
actually manifest in squamosa only. Upon that species, then, 
and not upon the one selected with doubt by Lamarck as the 
special type (an unfortunate choice, since it is characterised by 
him as being free from decussation in the hollows, “ costarum 
interstitiis non striatis”), must the epithet gigas be bestowed. 
Chana Hippopus. 
The Hippopus maculatus (Chemn. Conch. Cab. vol. vii. pl. 50, 
f. 498, 499) alone of the shells in the Linnean cabinet will agree 
