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Show 1895.] ON THE MUSCULAR ANATOMY OF XENOPUS. 841 portion of deltoid in Pipa. (3) Double nature of infraspinatus in Pipa. (4) Separate attachment of middle portion of triceps femoris to thigh in Pipa. (5) Origin of abdominal muscles from thigh in Pipa, instead from pubis as in Rana. In addition, a number of smaller differences will be apparent from a consideration of the foregoing account of the myology of Pipa surinamensis. 2. On the Diaphragm and on the Muscular Anatomy of Xenopus, with Remarks on its Affinities. By F R A N K E. B E D D A R D , M.A., F.R.S., Prosector to the Society, Examiner in Zoology to the University of London. [Eeceived October 31, 1895.] Having dissected and described *-I believe with greater detail than had been done previously-the " diaphragm," as well as the muscular anatomy generally, of the Surinam Toad (Pipa), I was anxious to see how far there was a resemblance with the African genus Xenopus (Dactylethra); for in spite of their wide separation in space and divergent external characteristics, many naturalists hold that these two genera are closely related, to which opinion expression has been given by placing them in one division of the Anura-the Aglossa. The opportunity of making the requisite dissections has been afforded by the death of a female specimen, presented to the Society a year or two since by Mr. P. Finn, F.Z.S., which was brought to m e directly after death, and was therefore in good condition. § The Diaphragm. Before proceeding to record the presence of various bands of muscle which I believe correspond to the complicated diaphragm of Pipa, I shall direct attention to certain of the viscera in the neighbourhood. The lung itself is in some respects intermediate between that of Rana and that of Pipa, as regards its fixation to the body-wall. In Rana the lungs lie entirely free in the coelom with the exception of their roots. In Pipa, on the other hand, a considerable length of the lung is firmly attached to the body-wall. Xenopus stands midway between these two extremes ; a fold of peritoneum of about half an inch in length ties the lung to the body-wall. There is also a pulmono-gastric attachment. Beneath the lung is a deepish pocket whose right and left walls are formed by these two mesenteries ; within this lies the terminal section and internal orifice of the oviduct. This aperture, it will be noticed from the figure (fig. 2), lies to the inner side of the lung; in Pipa the aperture of the oviduct lies quite to the side (inner) of the lung, and is borne upon a special fold of peritoneum, which I have illustrated in m y account of the anatomy of that batrachian. In Rana, on the other hand, the oviduct crosses 1 " O n some Points in the Anatomy of Pipa americana'' above, p. 827. |