* 
286 On the Conferee of Tasmania. 
of Callitris is retaiued. The differences between these are excel¬ 
lently displayed by Spach, in the “ Suites a Buffon” (Hist. Nat. 
des V<jg6t., v. 11, p. 345), though I should not attach the same 
importance to them as does that acute observer. The numerous 
scales of the Australian group are certainly a remarkable character. 
Yet that number and their relative size are so variable as con¬ 
siderably to diminish their value as a diagnostic mark. The 
ternary arrangement of the seeds, much dwelt upon by Brong- 
niart, as typical of the Australian form, is a striking and prominent 
character in our Cape species, whose seeds are hardly winged. 
The tuberculated receptacle is not constant in the Australian 
species, nor are the scales of the cones always alternately smaller. 
The wings of the seeds differ much jn size, some being quite as 
broad as those of Callitris or Pachylepis ; the seeds themselves 
are not always osseous; one species of the latter genus having 
the seed much more osseous than any Australian Callitris, 
and almost wingless. I have not been able hitherto to detect any 
difference, except that they bear three anthers or pollenthecee, 
between the male amenta of Callitris and Pachylejns, though 
Brongniart suggests that such may exist. The leaves of the Cape 
species are sometimes decussately opposite, and regularly so 
throughout a great part of the branches; those of the northern 
plant are arranged in fours, and of the Australain in threes. The 
latter is the most remarkable number amongst Coniferce, and is 
accompanied with two cotyledons, which is also the case in one 
species of the Cape Pachylepis. The pollen grains in Callitris, 
Frenela, and Pachylepis, are small, spherical, transparent, per¬ 
fectly smooth spheres, with an irregular, darker nucleus; in a 
young state they appear more flattened, resembling disks, and 
are larger. The two Tasmanian species belong to Brongniart’s 
genus Frenela, its most evident character lies in the ternary 
arrangement of the leaves. Spach rightly supposes that these, 
in a young state, are acicular, like those of Thuja, §c., 
1. C. australis, Br.; strobilis glomeratis solitariisve breviter 
pedunculatis globosis (magnitudine coryli avellanse), valvis 
lignosis crassis late ovatis valde obtusis v. sub-acutis laevibus v. 
longitudinaliter rugosis, receptaculo vix rugoso, column a centrali 
