74. SPECIES OF THE SYSTEMA. 
justly held of specific extent by Reeve, in his recent monograph 
of the genus Lucina. The one, the V. tigerina (ed. 10, p. 688, 
No. 112) of the Indian Ocean, is described by Linneus as de- 
cussated by crenated striz ; the other, the tropical V. orbicularis 
(ed. 10, p. 688, No. 118) is characterised, in contradistinction, 
as compressed, and as having its radiating sculpture more 
strikingly apparent than its concentric. These are precisely 
the distinguishing peculiarities of the decidedly convex L. ex- 
asperata (Reeve, Conch. Icon. Lue. pl. 1, f. 4), in whose coarse 
decussation the concentric, if either, preponderates over the 
radiating sculpture, and of the flattened ZL. tigerina (as repre- 
sented in the Encycl. Méth. Vers, pl. 277, f. 4). In confirma- 
tion of this, a specimen of the latter was found, marked (118, 
136) for V. orbicularis, of the former (112) for tigerina, in the 
Linnean collection. 
The figure of Rumphius (t. 42, f. H), cited for tigerina, fairly 
represents exasperata, and the “ exasperata striis elevatis trans- 
versis undatis crenatis, et striis minoribus longitudinalibus. 
Margo scaber, atro purpureus” of the ‘Museum Ulrice’ is cer- 
tainly more adapted to that shell than to the other. 
It is not, perhaps, expedient to change the accepted nomen- 
clature, for the name tigerina has been almost invariably 
accepted for the tigerina var. of the twelfth edition. 
Venus prostrata. 
Plate 1, figure 7, of this work exhibits the example marked 
for this species in the Linnean cabinet. It is the Artemis 
prostrata of Reeve (Conch. Icon. vol. vi. pl. 4, f. 23), whose 
excellent figure was not published when the three first plates 
of this work were engraved. It is not the V. prostrata of 
Chemnitz, but agrees well with the figure in Born’s ‘ Testacea’ 
(pl. 5, #6). 
The peculiarities of sculpture are not mentioned in the 
details of the ‘Museum Ulrice’; possibly, then, the shell there 
described was not identical with that of the earlier publication. 
