. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. ANATOMY OF VERTEBRATES. 175 110 and Scincus, the ckyicle expands at its medial lialf, which has a large vacuity or perforation occupied Ijy membrane. In the Chameleon tlic scapular arch is as simple as in tlic Crocodile, Ijut the coracoid is shorter and broader. The humerus in Lacertians is iisually larger and straighter, fig. 50, Driico volans, than in the Crocodiles, with a more compact wall and Avidcr mcdidlary cavity. Tiie radius, ib. and fig. 110, h, r34, is aluiost straight, and slender, witli an oval proximal arti
. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. ANATOMY OF VERTEBRATES. 175 110 and Scincus, the ckyicle expands at its medial lialf, which has a large vacuity or perforation occupied Ijy membrane. In the Chameleon tlic scapular arch is as simple as in tlic Crocodile, Ijut the coracoid is shorter and broader. The humerus in Lacertians is iisually larger and straighter, fig. 50, Driico volans, than in the Crocodiles, with a more compact wall and Avidcr mcdidlary cavity. Tiie radius, ib. and fig. 110, h, r34, is aluiost straight, and slender, witli an oval proximal articular concavity, and a distal surface partly convex, partly concave. The ulna, fig. 110, a, 55, shows tlie olecranon better developed than in the Crocodile: its dis- tal articular surface is convex. The digits are five in number, the phalanges are 2, 3, 4, 5 and 3, counting from the metacarpal of the first to that of the fifth digit: each has a claw supported on a moderately long, compressed, curved, and pointed phalanx. Tlie Cliameleon offers an exception to the numerical rule, the phalanges Ijcing 2, 3, 4, 4, 3 ; and the direction of the digits modified for the scansorial function in these arboreal Lacertians: I, 11, and iii, enveloped by the skin as tiir as the claws, are directed forward ; iv, and v, similarly sheathed, are directed backward : and the joints are shorter and broader than in Land-lizards. The fore limbs in Draco volans accord with the usual lacertian type, and take no share in the support of the parachute. But in the extinct order of truly volant Reptiles {Pterosauria) they were modified for the exclusive snjiport and service of the win^s. The scapula, fig. Ill, 51, long, narrow, flattened, and slightly expanded, lay more parallel with the spine tlian in land and sea Reptiles. The coracoid, strong and straiglit, and coinl)ining, as nsual, witli the scapula to form the glenoid cavity, articulated at the opposite end with a groove at the fore-part of a discoid
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1860
