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Show 596 MR. A. H. GARROD ON THE [Nov. 3, the specimen presented by Mr. Murdoch to the Society, I have twice bad the opportunity of dissecting Stringops habroptilus. As a Parrot it is not so strikingly peculiar as many seem to think. Its wings are useless, and the carina sterni is correspondingly reduced, it is true ; but as points of classificational importance, I regard these as insignificant. The points of special anatomical interest which it does possess, however, are particularly instructive. The proximal ends of the incomplete furcula are well developed, so much so that it might at first sight seem that their symphysial ends are only lost in correlation with the excessive reduction of the powers of flight; though this is probably not the case, because the allied similarly modified genera Euphema &c. do not keep to the ground. Further, in the Society's specimen above mentioned, though the ambiens muscle did not cross the knee, yet its fleshy belly was well differentiated on both sides, its thin tendon being lost over the capsule of the joint. In the College of Surgeons' specimen, however, this muscle was entirely absent in the only knee which was in a fit state for dissection, the other being much shot. It is only in the genus GUdicnemus that I have elsewhere found a similar partial loss of the ambiens*. The partial development of this muscle in this particular instance shows that the tendency to lose it is not of great antiquity ; and it is to be noted that there is no other Parrot with normal carotids in which any trace of an ambiens is to be found. These considerations suggest, what may perhaps be the case, as is suggested by the peculiarities of their geographical distribution, that Agapornis may be the representative among the normal-carotid Parrots of the Platycercine branch from the Arinae, whilst the Stringopinae proper (including Geopsittacus, Melopsittacus, and Euphema) are more direct continuations of the main stem, as indicated by the dotted portions of the diagrams (Plates L X X . and L X X L ) , Stringops itself being the nearest living representative of the common ancestor of the whole suborder. Further, it may be worth while taking a glance at some of the most important changes which m y classification would necessitate. Taking Mr. Sclater's '• Revised List of Vertebrated Animals in the Society's Gardens' as a good representative of current opinion, the Order PSITTACI is there divided into two families and seven subfamilies, thus:- Order PSITTACI. Family I. S T R I N G O T I D ^ E. Family II. P S I T T A C I D ^ E. Subfamily 1. CACATUINJE. ,, 2. ARINAE. „ 3. PLATYCERCINAE. „ 4. PSITTACIN^E. „ 5. LORINJE. ,, 6. NESTORIN.<E. * Vide P. Z. S. 1873, p. 640. |
