Jan. 26, 1888.] 



FOREST AND STREAM. 



8 



we find that we can still retain our old sections,the Arti- 

 odactyla and Perissodactyla, as two clearly defined sub- 

 orders of the Ungulata, and designate them as the 

 Ungidata vera; while we throw all the other species, 

 upon whose structure we are not nearly so well informed, 

 into other sub-orders, and collectively term them the 

 Subungulata, or in contradistinction to the first, the 

 Ungulata polydactyla. 

 This arrangement may be still more clearly shown thus: 

 Suborders. Exampks. 



Ungulata.. 



Ungulata Vera.. 



1 Artiodactyla.... ] Swine, Ox, Deer. 



! Perissodactyla.. 



Horse, Tapir, Rhi- 

 noceros. 



Hyracoidea jHyrax. 



Subungulata. Proboscidea . . . . -j Elephants. 



i Dinocerata and 



Amblypoda •< other extinct 



( forms. 



Very excellent anatomical characters distinguish the 

 Artiodactyla from the Perissodactyla, which our limited 

 space will forbid entering upon here, but we will be per- 

 mitted to notice the chief among these, and I refer to the 

 differences which obtain in the skeleton of the feet of 

 these two suborders. Aside from now well-known dif- 

 ferences which exist in the arrangement of the bones of 

 the wrist and ankle joints, we find tbat the artiodacty- 

 line animals are even-toed, as in the deer, pig and camel, 

 the median line of the foot passing down between the 

 third and fourth digits (see C and D of the figures). Now 

 the perissodactyline animals are odd-toed, as in the horse 

 and rhinoceros, the median line of the foot passing longi- 

 tudinally down the center of the third digit (see A and B 

 of the figures). It will at once be noticed that these 

 types of feet are very different from what we find in the 

 great elephantine ungulates, as in the elephant (see Fig. 4). 



In the present connection it will be obviously impossible 

 to enter upon the natural history or structure of the 

 highly interesting species falling under the Stibungulata. 

 None of them are now represented in the existing fauna 

 of the United States. 



Taken as a whole, then, these are some of the distin- 

 guishing characters of the Ungulates: For the most part 

 they are vegetable feeders, and of a terrestrial habitat; 

 they are without a collar-bone; they walk on their toes, 

 which latter are either armed with a trae hoof, or pro- 

 tected by nails, which are broad, blunt and rough; their 

 teeth are well developed and arrayed upon definite plans. 

 A study of the skeletons of existing species, and the long 

 array of extinct ones, recently brought to light, show a 

 vein of kinship running through the entire group, linking 

 them more or less closely together, and even in some in- 

 stances pointing to a relationship with other orders, ,as 

 perhaps the Rodents on the one hand, and the Sirenia on 

 the other. 



As engaging a subject as the study of the entire group 

 of existing Ungulata proves to be, with its elephants, its 

 quaint little puzzle the Hyrax (of several species); its vast 

 variety of Horses; the Rhinoceroses; the Tapirs; the 

 different types of Swine; all the Cavicorn ruminants; 

 and all the numerous species of deer and their allies; the 



Camels and their lrir)d; aa interesting no I n»j this study 



io, its interest is simply trebled, when we come to trace 

 back through the fossil forms referred to above, the ex- 

 traordinary types which were the ancestors of this now 

 living host of animals. 



In a short article like the present one it will be out of 

 the question to trace back into geologic times, even a few 

 of these extinct lines of ancestors of existing ungulates, 

 but to quote quite fully from Le Conte, "it will be inter- 

 esting and instructive to run out one of these branches 

 and show in more detail the genesis of one of the extreme 

 forms. For this purpose we select the horse, because it 

 has been somewhat accurately traced by Huxley and by 

 Marsh. About thirty-five or forty species of this family, 

 ranging from the earliest Eocene to the Quaternary, are 

 known in the United States. The steps of evolution may 

 therefore be clearly traced. In the lowest part of the 

 Eocene basin (Coryphodon beds) of Green River, is found 

 the earliest-known animal, which is clearly referable to 

 the horse family, viz. , the recently-described Eohippus, 

 of Marsh. This animal had three toes on the hind foot 

 and four perfect serviceable toes on the fore foot; but, in 

 addition, on the fore foot an imperfect fifth metacarpal 

 (splint), and possibly a corresponding rudimentary fifth 

 toe (the thumb), like a dew-claw. Also the two bones of 

 the leg and fore arm were yet entirely distinct. 



"This animal was no larger than a fox. Next, in the 

 Middle Eocene (Bridger beds) came the Orohippus of 

 Marsh, an animal of similar size, and having similar 

 structure, except that the rudimentary thumb or dew- 

 claw is dropped, leaving only four toes on the forefoot. 

 Next came, in the Lower Miocene, the Mesohippus, in 

 which the fourth toe has become a rudimentary and use- 

 less splint. Next came, still in the Miocene, the 

 Miohippus of the United States and nearly allied 

 Anchithere of Europe, more horse-like than the preced- 

 ing. The rudimentary fourth splint is now almost gone, 

 and the middle hoof has become larger; nevertheless, the 

 two side hoofs are still serviceable. The two bones of 

 the leg have also become united, though still quite 

 distinct, jjjhis animal was about the size of a sheep. 

 Next came, in the Upper Miocene and Lower Pliocene, 

 the Protohippus of the United States and allied Hip- 

 parion of Europe, an animal still more horse-like than 

 the preceding, both in structure and size. Every remnant 

 of the fourth splint is now gone; the middle hoof has 

 become still larger, and the two side hoofs smaller and 

 shorter, and no longer serviceable, except in marshy 

 ground. It was about the size of the ass. Next came, in 

 the Pliocene, the Pliohippus, almost a complete horse. 

 The hoofs are reduced to one, but the splints of the two 

 side toes remain to attest the line of descent. It differs 

 from the true horse in the skull, shape of the hoof, the 

 less length of the molars, and some other less important 

 details. Last comes, in the Quaternary, the modern 

 horse — Equus. The hoof becomes rounder, the splint 

 bones shorter, the molars longer, and the second bone of 

 the leg more rudimentary, and the evolutionary change 

 is complete.'" Professor Le Conte took his figures from 

 Marsh, and I copied them from the former. In mine the 

 figures of the limbs and the teeth of these extinct and 

 modern horses were not drawn. Cope has traced out the 

 descent of the camel in very much the same manner, and 

 this latter writer has of recent years marvellously added 

 to our knowledge of these highly important extinct types, 

 and in admirable schemes of classification, too extensive 



CO. 



Fig. 2.— Left lateral view of the head of a male Babirussa, considerably reduced. 



Fig. 3.— Head of a male Wart-Hog {Plmcochwrus africanus); reduced. Figs. 2 ane 3 designed to show the extraordinary development 

 of the canines in some of the relatives of the Peccary. 



Fig. 4.— Right forefoot of Indian Elephant; greatly reduced. (After Flower.) 



Figs, a.—f,— Forefeet of Equus and its extinct kin. «- Orohippus (Eocene); b. M- esohippus (Lower Miocene); c. Miohippus (Miocene): 

 <l. Protohippua (Lower Pliocene); e. Pliohippus (Pliocene); /■ Equus (Quaternary and Recent). 



Figs. A..—D — A. ji. Feet of Perissodactyles; V. D. Feet of Artiodactyles. A. Tapir (Tapirus indicus); JB. Horse {Equus caballus); 

 C. Camel (Cameius baclrianus); J>. Pig (Sus scrofa). -J- and Ji are Xl-5, V x%, and X> x%. (After Flower.) 



to be_ dwelt upon here, has shown the probable origin of 

 existing families of Carnivores, Insectivores,Quadrumana, 

 etc., from his Bunotheria; and as we have pointed out 

 above, the various families of the order now under con- 

 sideration, from the generalized extinct types of the 

 Amblypoda. The study of the evolution of structure 

 that is displayed in the remains of these ancient forms, 

 as compared with the anatomy of species still living on 

 the earth, affords a lesson pregnant with facts of the 

 very highest importance, and well worthy of the pro- 

 foundest contemplation of the trained zoologist and 

 philosophic naturalist. 



"We pass now to a brief consideration of the life-history 

 of the Peccary. There are but two species of these ani- 

 mals, both being confined to the American continent: 

 the larger of the two, the white-lipped peccary, being re- 

 stricted to a range between British Honduras and Para- 

 guay. This animal {D. labiatus) has a length of about 

 40in. , and is characterized by its white lips and lower 

 jaw; its general color being nearly black; and as in all 

 wild swine, its young are longitudinally striped in their 

 markings. A South American observer says, ' 'This species 

 lives in large bands, sometimes amounting to a thousand, 

 and stretching out for a league, migrates from one dis- 



