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Show 48 ZOOLOGY OF TilE YOY.A.GE OF TilE BEAGLE. h f 1 'ddle as compared with the lateral chene in the greater size and strengt o t 1e mi metacarpal . · 1 h 1 (fi O' 5 T he articul ation at the di stal extremity of the proxima P ~ an.ges . o· : P l. .. / I.) i imple, and not divided into two pulleys by a longJtudmal. n dged 1t 1 lirrhtl concave from side to side; but in its extent upon the an~enorfanh 0 posterior su• rface of the bone . d' f. d of flexion and extenswn o t e 111 1cates a ree om. . toe which harmonizes with the tructure of the JOint above. P l X I The proximal articulating surfaces of the second phalanges (fig: 7 • · ·_) corrc pond of course to those to which they are adapted; they ~J e, howeve~, chara t rized by sending upwards an obtuse proces from the middle of their anterior maro·m· . The d1· tal art1· cu ) atm· g· sur1c. aces (fi a . 8 , Pl · XI · ) re.s emble tho e of the proximal phalanges, but extend fu rther up.o~ the back part of the pl~alanx than the front, indicating the more horizontal po 1hon of the second phalanoes. The la t phalanx, does not resemble the neatly defined ungula~e ~halanO'eS of th Ruminantia, and Solipedia, but ha the irrecrular form characten.stic of tho e of the Pachydermata. It i wedge-shaped, broader than it is long, w1th a rUO'O'ed urface, e.·cept wher~ it play' upon the distal end of the second phalanx, where 1t 1 lirrhtly concave in one direction, and convex in the other, (fig · 7 ~nd 9, Pl. XI.) A portion of this phalanx extends backward behind the articular urface, a in the corre ponding bone of the Pal ~othere and Rhinoceros. The femur of the Macrauchenia (fig . 1, Pl. Xl l.) is full two feet in length, and con equently lono·er than in any known Camel or Rhinoceros; as com1~ared with it trau ver e diameter it i much longer than the femur of the latter ammal: in tb proportion of it breadth to its length, and the expan ion of its extremitie a com par d with the diamet r of the haft, it more re emble that of the amel. Th femur of the Giraffe d viate from that of the 1\Iacrauchenia in the exce sive e pan ion of its di 'tal extremity. But the most triking evidence deducible from thi bone, of the affinity of the Macrauchenia to the true Pachydermatou type i afforded by the evident trace of a third trochanter, the outline of which i, conjecturall re tored in the figure. Of the Pachyderms which have thi charact ri tic tructure, the e ·tinct Pal~othere offers the nearest resemblance to th Macraucbene in tb rreneral form and structure of the femur. The h ad of the femur in the 1\facrauchene (fig. 2, Pl. XII.) pre ent the form of a pretty reo-ular hemisphere; it i lc fiatt ned above, and i directed more obliquel inward than in the Palreotbere: the neck upportino- it doe not project o far from the haft a in the Pal~othere or Tapir, but farther than in the amel. The rrreat trochanter ri e above the level of the head; in which ~tructure and in the depr ion between the h ad and trochanter, the femur of the :\facrauchene offer a character intermediate b tween the Tapir or Palreothere, and the Camel. The le · er trochanter i a light projection from a ridO'e FOS IL MAMMALIA. 49 of bone which is continued from the under part of the head of the femur to the inner surface of the shaft. In the Pal reothere the lesser trochanter is s ituated more towards the posterior surface of the femur; so that, in this particular, the Macrauchene approaches nearer to the Camel. Cuvier makes no mention of the condition of the depression for the ligamentum teres in the Palreothere. Among existing ordinary Pachyderms the Hippopotamus presents no trace of the insertion of a ligamentum teres in the head of the femur; in the Camel the place of its insertion is indicated by a well-marked circumscribed pit; in the Tapir a similar circular depression is situated close to the inferior margin of the articular convexity. The ligament was undoubtedly present in Macrauchenia, but the place of its insertion is a broad and deep notch leading from the under and back part of the head of the bone a little way into its articular surface : this I regard as another of those interesting transitional structures with which the remains of the Macrauchenia, few and imperfect though they unfortunately arc, so freely abound. The femm of Macrauchenia, in the flatn ess of the back part of its neck, and the elongated form of the post-trochanterian depression, resembles that of the Camel rather th an th at of the P alreothere ; and the same resemblance is shown in the cylindrical figure, straightness, and length of th e shaft. The depth of the trochanterian depression, and the incurvation of the strong ridge continued downwards from the great trochanter are individual peculiarities in the Macrauchenia. A great part of the third trochanter is broken off'; but from the remains of its base we see that it had the same relative size as in the Palreothere; but it is situated at the middle of the shaft of the femur, and consequently lower down than in the Palreothercs and T apirs. In the general form and relative size of the condyles at the distal extremity of the femur (fi g. :J, Pl. IX. and XII.) the Macrauchene is intermedi ate to the Camel and Pal ~ oth e re, but resembles more the latter. In th e articul ar surface for the patella, it deviates somewhat from the P ahcothere, having this part longer in proportion to its breadth, more regularl y and deeply concave from side to side, and with its 1ateral boundaries more sharply defi ned. In all these poin ts the Macrauchene approaches the Camel: the same affinity is shown in the protuberance above the inner condyle ; but in the extent of the posterior proj ection of thi condyle (fig. 3, Pl. IX.) it exceeds the Camel and P ala:!othere, and displays an intermediate structure between these species and the Hippopotamus. There is a rough crescentic depression above the outer condyle where the linea aspera begins to diverge; the corresponding depression is deeper in the Hippopotamus, while in the Camel it is represented by a roughened surface only, which is not depressed. In the fossa between the rotular articulation and the external condyle the Macrauchene resembles the Camel: the interspace of the H |