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upper one very small, and the middle and lower one large and nearly 
equal in size. 
On turning to the New-World species of the genus, we find four 
variations in the dentition of the mandibles; the group of pale spe- 
cies typified by M. equinoctialis, De}. (bifasciata, Brullé), corre- 
sponds almost identically in the dentition of both sexes with the old 
type (M. senegalensis), as described above, the right mandible having 
two equal-sized large acute teeth in the middle of the inner margin, 
and the left one also two, the upper one being very small. For this 
group I have proposed the subgeneric name of Ammosia, in allu- 
sion to their habits, which differ materially from those of the other 
species. 
an black-coloured species from South America (M. sepulchralis, 
Fabr., M. variolosa, Dej.) differs from the Ammosie in the left man- 
dible, while the inner margin has only one tooth in the middle, of 
considerable size, and exhibiting on its wader side a minute tooth, 
being all that remains of the large middle tooth of the left mandible 
of the dmmosie. This species is the type of Mr. Hope’s subgenus 
Anaira. 
Another very fine Brazilian species (M. testudinea, Klug) differs 
in the dentition of the sexes in a more striking manner than any of 
the preceding. The right mandible of the male is long and sickle- 
shaped, with a small tooth obliquely truncated below the middle of 
the inner margin, and between this and the tip of the jaw is a mi- 
nute acute tooth. The left mandible has two teeth on the inner 
margin above the middle, the lower one broad and acute, but rather 
obliquely truncate, whilst the upper one is very small. The right 
mandible of the female, on the contrary, has two very large equal- 
sized teeth in the middle of the inner margin, whereas the left jaw in 
this sex is quite similar to that of the male. 
There still remains a numerous group of American species (the 
type of which is Cic. Carolina, Linn.), which differ from the rest of 
their continental brethren in possessing three teeth in the middle of 
the inner margin of each jaw, thus resembling the Australian species 
above noticed, and hence I proposed the name of Tetracha, or four- 
toothed, for this group, counting the acute apical portion of the man- 
dible as a fourth tooth. In general, in both sexes, the tooth next 
below the apex of the jaw is equal in size to, or even larger than, the 
apical part or tooth itself (thus differing from the Australasian spe- 
cies), and the middle of the three teeth is smaller than the rest; but 
in the left mandible in the males the tooth below the apical tooth is 
even still larger, whilst the middle tooth is much smaller, and the lower 
tooth is quite minute. In the female, on the contrary, the middle 
one of the three teeth of the inner margin is rather larger than the 
upper one (which is only of a moderate size), and the lower one is 
small. 
From these particulars (united with the peculiarities of colouring, 
geographical range and habits of the species) we are enabled to pro- 
pose well-founded subgenera, a task which has hitherto been con- 
sidered hopeless in the genera of Cicindelide. The Old-World spe- 
lee 
