116 
the Ven. W. Williams from the bed of a mountain-stream descending to the coast at 
Poverty Bay, North Island, and is referable by its size to the Dinornis struthoides. ‘The 
smaller specimen (Pl. XXXL. figg. 3—6) was obtained by William Swainson, Esq., from 
the North Island, probably in the vicinity of the Bay of Islands, and has belonged to a 
species distinct from the preceding, and agreeing in size with the Dinornis dromioides. 
Both specimens have the ferruginous tint and great weight, arising from infiltration of 
a salt of iron (peroxide), which characterized the specimens from the North Island 
described in the former memoir; but the cancelli of the bone contain only a little of 
the dry powdery alluvium of the streams into which the specimens have been washed, 
Cranium. 
The cranium referred to Dinornis struthoides agrees pretty closely in size with the 
same part of the skull of the Ostrich, as will be seen by reference to Plate XVI, in 
which it is figured from four points of view, of the natural size; but it is broader in 
proportion to its height, especially in the occipital and inter-orbital regions. It is, in 
fact, remarkably depressed, subquadrate, with two large lateral emarginations for the 
temporal fossz (ib. 6, 6), and both in size and shape it is more like the corresponding 
part of the head of the Dodo (ib. fig. 5) than that of any existing Struthious species : 
but the upper surface of the cranium of Dinornis is gently and equably convex above, 
the cerebral hemispheres not raising their bony covering above the level of the rest of 
the calvarium, as in the Dodo; and the frontal region, though more elevated than in the 
existing Struthious birds, is less suddenly raised than in the Dodo. The length of the 
present fossil is three inches, but half an inch at least of the anterior border of the 
os frontis has been broken away: its breadth across the mastoids is three inches and a 
quarter, but the breadth across the post-orbital angles appears to have been greater. 
The breadth between the temporal fossz, which are large and deep, is two inches five 
lines; its vertical diameter at the deepest part, from the upper occipital ridge to the 
under surface of the basi-sphenoid, is one inch and a half. From the occipital region 
the depth of the cranium gradually decreases to the anterior boundary of the cerebral 
cavity. The great occipital foramen (fig. 1, 1’) is subcircular, and seven lines in dia- 
meter,—that of an Ostrich being five and a half lines across: its plane is vertical, and 
the single occipital condyle (¢b. 1) projects freely backwards, upon a short peduncle, 
beyond the upper margin of the foramen. No existing bird presents this peculiarity : 
the Dinornis in this respect resembles some of the Chelonian Reptiles. The broad and 
low occipital surface of the skull slopes forwards as it rises to join the upper surface. 
This inclination, with the slight depth and great breadth of the occiput, and the almost 
flat upper surface of the skull, forms the most peculiar features of the present cranium. 
The occipital region above the foramen magnum is divided by three short obtuse vertical 
ridges into four depressions (fig. 3, d), the two median ones being half the breadth of the 
two lateral ones, which are deeper than usual: each depression is bounded above by a 

