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Show 512 MESSRS. BEDDARD AND PARSONS ON [June 6, almost uniform arrangement of the patagial tendons. In them the three tendons are very difficult to distinguish because the fibrous membrane between them, of which they are only specialized parts, is as thick as they are. The result is that in these birds the patagial muscle seems to be inserted by a broad, short, membranous- looking tendon. Conurus shows a transitional stage between these last genera and the typical arrangement; the three tendons are more distinct, but they are equally short and show the same mode of attachment to the fleshy part of the muscle. Lathamus is remarkable for having the anterior tendon separate in its whole length from the middle one, instead of being fused with it in the upper part of its course. Chrysotis and Bolborhynchus have a small extra tendon between the middle and posterior ones : in G. guildingi this was only present on one side, but in C. leucocephala it was found on both. Psittacus has three tendons which are completely separate in the whole of their course, and in this respect it corresponds to Lathamus. W e are, however, inclined to look upon the anterior tendon as representing the fused anterior and middle tendons of Lathamus, and to regard the middle tendon as an extra one as in Chrysotis. Our reasons for this are that there is a considerable interval between the two tendons, and that they do not diverge as in all other cases. If this view is correct, the patagial tendons of Psittacus closely resemble those of Chrysotis, while they also agree in having the anterior deltoid larger than the posterior, in the absence of a lower head to the anconeus, and in having the deltoid completely covered by the tensor patagii. Tibialis anticus.-The tibialis anticus in almost all the genera which we examined was inserted by a single tendon except in Chrysotis (of which two species were examined), where this tendon was double. The only genus which resembled Chrysotis was Psittacus, in which the tendon was really double ; but the two parts, although easily separable, were slightly connected together. In several other genera we detected a slight line of demarcation in the tendon, but it was not sufficiently definite for us to regard it as of any classificatory value. Peroneals.-The peroneus longus and brevis are, as far as we have observed, always present in Parrots, but the origin of the former differs somewhat in different genera. In Stringops and Nestor the peroneus longus rises from the front of the bony fibula and its membranous continuation for about the upper half of the leg. The muscular belly overlaps that of the peroneus brevis very much near its origin, and the muscle is large and well marked. In Chrysotis, on the other hand, the peroneus longus is very small and only rises from the membranous continuation of the fibula in the lower part of the leg ; it is so small that it does not overlap the peroneus brevis at all but lies behind it. |