296 Mr. G. Krefft on a new Species of Thylacine. 
he still holds to his original assertion as to the existence of 
perforations in these shells. 
When Prof. King shall have shown the least ground for 
the belief that shell-tissue of the most peculiar and charac- 
teristic kind can be formed during the process of fossilization, 
so as to fill vacuities that existed in the recent shell (which is 
just as if, in the silicification of a piece of wood previously 
perforated by large holes, these holes should be filled up by 
true woody tissue), his assumption that the whole of Mr. Da- 
vidson’s type specimen of Spirifer cuspidatus and that the 
imperforate spaces in the shells of Syringothyris were origi- 
nally perforated may deserve consideration. Until then, I 
venture to think that the imperforateness of the former type, 
and the patchiness of the perforations in the latter, are esta- 
blished by Prof. King’s confessed inability to set aside the 
facts stated by me on these points, as the direct results of 
careful and experienced observation. 
Trusting that this is the last occasion on which I shall feel 
it necessary to address you on this subject, 
I remain, Gentlemen, 
Your obedient Servant, 
WILLIAM B. CARPENTER. 
XXXV.—Description of a new Species of Thylacine (Thyla- 
cinus breviceps). By GERARD KReEFFT, Curator and Secretary 
of the Australian Museum, Sydney. 
[Plate XVII. ] 
SKULL shorter (63 inch.) than that of T.cynocephalus (74 inch.) ; 
the palatal openings much reduced in size; occipital foramen 
larger than in the well-known species. The anterior part of the 
skull is not much compressed ; and the sharp nick so prominent 
in all skulls of 7. cynocephalus, between the second and third 
premolars, is wanting in the present species. The greatest dif- 
ference exists in the teeth, which in the new species are very 
large, the most prominent being the second and third molars 
in both jaws. ‘The canines are thicker, and form a shorter 
curve; the outer incisor of the upper series is also very much 
larger than the corresponding tooth in 7. cynocephalus. 
I enclose three photographs of the skulls of both animals* 
in different positions, both very perfect, and that of 7. cyno- 
cephalus larger than that of the new species. The last molar 
in 7. breviceps has been lost from both specimens (in posses- 
sion of the Trustees of this Museum) ; but the sockets indicate 
* We have given in the Plate the figures of the new species only.—Ep. 
8 Ss ¥. 
