FR. Cowper Reed—Silurian, Haverfordwest. - 535 
3. The Adaptive Creodonts are more primitive than the Fissipedia, 
while the Inadaptive Creodonts have reached an equal grade of 
specialization in enamel structure as in other respects. 
4. Borhyena is more highly developed than any modern marsupials, 
equalling the modern Carnivora in its enamel specialization. Whether 
this applies to the other Sparassodonta with less specialized dentition 
is not known. 
The above conclusions harmonize very readily with the evidence 
from the morphology of the teeth, skull, and skeleton in the 
Carnivorous Marsupials, Creodonts, and modern Carnivora. They are 
certainly not in accord with Dr. Lydekker’s view that the Marsupials 
are derived from Creodonts. The highly developed enamel structure 
of Borhyena may be best interpreted as meaning that certain of 
the South American pseudo-Carnivora were more progressive and 
specialized in the histology of their teeth than any of the modern 
Australian pseudo-Carnivora, as they certainly are in many other 
features of their osteology and dental evolution, in each case 
paralleling (for obvious mechanical reasons) the Placental Carnivora. 
The loss of epipubic bones and of palatal vacuities might also be 
expected as a consequence of their more progressive character, while 
their marsupial derivation and relationship is attested by practically 
all the remaining characters distinctive of the order. 
As regards the position of the Creodonts, the writer has had the 
opportunity during the last three years of studying a collection far 
more extensive and complete than has ever been known before, and hopes 
shortly to publish the results of these studies. It is sufficient to say 
at present that the evidence is entirely in accord with the conclusions 
derivable from the valuable data on the histology of the teeth given 
by Mr. Tomes; that the Creodonts were nearly related to the modern 
Carnivora, and show no considerable approach to the Marsupials; that 
the Inadaptive Creodonts (Creodonta of Wortman and Lydekker) are 
not intermediate between Carnivora and Marsupials, but parallel the 
modern Carnivora, specializing earlier than the Adaptive group 
(included in Carnivora by Wortman), which latter approximates the 
Marsupials to a limited extent by retention of several - primitive 
characters. These conclusions have been maintained in recent years, 
and the antiquity of the division between Marsupials and Placentals 
emphasized especially by Osborn, Scott, and the writer in_ this 
country, and by most European authorities; the additional evidence 
confirms them throughout. 
III.—Srpewicxk Museum Norss. 
Tue Base oF THE SILURIAN NEAR HAVERFORDWEST. 
By F. R. Cowrrr Resp, M.A., F.G.S. 
N several previous occasions! the author has described in the pages 
of the Grorogicat Magazine certain fossils from so-called ‘‘ Slade 
Beds” from the roadside near St. Martin’s Cemetery, Haverfordwest. 
1 Reed: Grout. Mac., Dec. V, Vol. II, 1905, pp. 98, 100, 103, Pl. IV, 
Figs. 8-12; ibid., pp. 447, 448, 449, 451, 453, Pl. XXIII, Figs. 3, 4-7, 9, 16; 
ibid., pp. 493, 494, 497, 498, 500, Pl. XXIV, Figs. 1-10, 14, 15; ibid., Vol. III, 
1906, p. 361. : 
