XII. Evidence of a large extinct monotreme (Echidna Ramsayi, Ow.) from the Wellington Breccia Cave, New South Wales

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Abstract
Amongst the detached bones and fragmentary evidences of Mammals from the abovenamed locality, submitted to me by Edward P. Ramsey, Esq., F. L. S., who thence obtained them, was a humerus sufficiently complete to yield the following characters. It was of great breadth in proportion to its length, and, through the unusual size and direction of the processes and ridges for muscular attachments, seemed as if the shaft of the bone had been twisted half-way round on its axis. The head, or proximal articular surface (Plate 14, fig. 1, a , and fig. 3), is a transversely elongated convexity, of a narrow ovate shape, with the broader end toward the ectotuberosity, b —the direction of such joint being at right angles to that of the feline humerus, in which, as in Thylacoleo , the antero-posterior or then-anconal diameter prevails. The non-articular portions of this end of the bone extend for equal distances to the ento- c - and ecto- b -tuberosities. From the latter is continued the “deltoid” or “anterior bicipital” ridge, f , from which, after its course of more than one-third the length of the shaft, it is continued by a lower ridge along the thenal aspect to be lost in the bony bridge overarching the neur-arterial canal, k , v . From the ento-tuberosity, c , is continued the “teretial” or “posterior tricipital” ridge, along the radial border of the humeral shaft to its termination in a special process —the "tricipital,” d . Moreover, both ento- and ecto-tuberosities are connected together by a low curved ridge or rising which bounds a small portion of the palmar surface of the shaft immediately below the head of the humerus. From the bridge, k , is continued a narrow ridge to the ent-epicondylar process, i . The distal end of the humerus is continued, ridge-like, from i to a process j midway between the epicondyles, h and i , but bounding the ulnar trochlea, u . A notch below the outlet of the neur-arterial canal, k , indicates the ulnar trochlea and divides the process, j , from the articular tuberosity or condyle, l , for the head of the radius. A very small proportion of this condyle is continued upon the anconal surface of the humerus (Plate 14, fig 2); the convexity there changes to a concavity, u , for the ulna, and from e is continued the ectepicondyle, h , as a well-marked outstanding process.

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