ON somp: new and little known ceeodonts. 
KM 
shortness of tlic middle cuneiform. Nos. V and IV have an inwardly directed 
proj'ection whicli fits into a corresponding cavity in tlie adjacent metatarsal. Nos. II 
and 111 are not interlocked at all. 
The phalanyes are like those of the fore-foot, but longer and more slender. 
As a whole, the high and narrow' pes is A'ery different from that of the planti- 
grade and much like that of the digitigrade CarniA'ora, especially Hyama, to wdiich 
the resemblance is very close, even in details. 
(Vhat I believe to be the distal end of the os lyenis is represented in the speci- 
. men. It is curved ni)w ards and ends in a small knob, resembling the corresponding 
l)one in some of the Mustelidm.) 
Restokation. — The skeleton of Mesonyx as a whole is very curiously propor- 
tioned. The head is very large, the trunk very long, with prominent spines in the 
dorsal region, the flanks slender, and the tail long and cat-like. The thorax is 
shallow and compressed. The limbs are very short and the feet especially -weak. 
AN'ith a body as long as that of a full-grown black bear, the animal did not stand as 
high from the ground as a large dog, and compared with the bear the limbs were not 
mu.scnlar, not more than in the hytena. When alive, the creature must have had a 
very grotesque a])pearance. Indeed its peculiarity might excite the suspicion that the 
drawing was incorrect, but the specimen is .so perfect that the only room for que.stion 
is as to the length of the femur and of a few ribs, and the exact number of joints in 
tin* tail. Possibly also the animal possessed a greater number of dorso-lumbar 
vertehne ; but this is very unlikely, as those pre.served seem to indicate an unbroken 
series, without any percejdible gaps. It is also, perhaps, a question as to w hether the 
animal was jdantigrade, as Professor Cope believes, or digitigrade as I have repre- 
sented it. My rea.sons for this course are: (1) The length and narrowness of the 
feet, which are in sharp contrast to the feet of the plantigrades; (2) the reduction in 
the «ligits, wliich .seems to have gone as far as in any living carnivore; (3) the extra- 
ordinarily iKM-fect interlocking of the metacarpals, which is not a'pproached in the 
Arctoi(h.a and excelled only in the cats; (4) the very long narrow tarsus and cliarac- 
tei ol the astragalar trochlea; (o) the very close general resemblance to the feet of 
itl, the iiossible exception of Pachycena no known creodont can show 
such a sjieciahzed foot structure as Mesonyx. 
-Vekinities.— The relations of tlie Mesonychidee to any other group are very 
osc-ure. -rom tlie .study of imperfect specimens I w as formerlv led to consider them 
clostdy allied to //yovuWou, but as Profe.s.sor Cope has shown, the resemblance in the 
dentition IS rather a .supeihcial than a fundamental one, and the limbs are very differ- 
ent 1,1 the two forms, llya^nodon has five functional digits in the manus, with a short 
bioad plantignnle foot. Mesonyx cannot be regarded as an ancestor of Hycenodon, a.s 
the latter ,s in many respects more primitive than the former. 
In Me>.nn,x we are presented with a most curious assemblage of characters. 
