The Meaning of some of the Epiphyses of the Pelvis.

IN the Morphologisches Jahrbuch are two very interesting papers by Dr Ernst Maynert I dealing with the epipubis and hypoischium of Reptiles, in which he points out that these structures are formed in the mid ventral line, and probably are, in the first instance, independent of the rest of the pelvis. It is to the fate of these structures in the Mammals that I wish to -call attention, but, before doing so, I must make a few remarks about the reptilian arrangement. With regard to the hypoischium, Maynert shows what a variety of forms it may take, sometimes being specially elongated, sometimes almost entirely suppressed, sometimes bifid at its pelvic end, at others toward the cloaca, sometimes fully ossified, sometimes entirely cartilaginous, but always forming a more or less perfect support for the anterior lip of the cloacal orifice, and earning its alternative name of ' Os cloacae.' Of all the reptilian pelves which I have examined, I think perhaps that of the Sphenodon Lizard (fig. 1) will give the fairest idea of this structure. It (the hypoischium) is attached anteriorly between the junction of the two ischia which are uniting to form the ischial symphysis so common in Reptiles; if it is carefully examined, it will be seen to continue forward between the two ischia and then to reach the interval between the two pubes, anteriorly to which it expands to form a diamond-