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Show 440 MR. F. E. BEDDARD ON THE [June 3, Not much, as it appears to me, can be gathered from the above facts as to the relationship of Podica : it is not distinctively Ralline nor is it, on the other hand, distinctively Colymbine. In Porzana and Gallinula (Giebel) there is a fusion between a number of tbe dorsal vertebrae. The coracoid is a stout bone; the mesocoracoid process (Parker, 11) is continued into a long thin ridge, which extends along nearly the whole of the inner edge of the bone, gradually decreasing in depth. This process is much larger than in any Rail which I have examined, but not so large as in Psophict (cf. P. Z. S. 1890, p. 336). In the Grebes the process in question is obsolete or rudimentary. The clavicle has been already partly described in connection with the sternum ; it is attached above to the mesocoracoid process and to the acromion. In Heliornis the furcula is also firmly attached to the carina sterni, but Giebel has omitted to mention anything about the anterior and posterior interclavicular processes. The articulation of the clavicle is a point upon which Fiirbringer lays some importance ; it allies Podica with the Rails and not with the Divers, in which birds the clavicle extends beyond the acromion. The Heliornithidce thus agree with the Rails in the following characters: - (1) In the general structure of the skull. (2) In the general form of the pelvis. (3) In the pterylosis. (4) In the presence of an expansor seconclariorum and in the relation of the tendons of this muscle. They agree with the Colymbiclce in the following :- (1) The insertion of the biceps slip on to the patagium instead of on to the tendon of the patagialis longus. (2) In the characters of the latissimi dorsi. (3) In the muscle-formula of the leg, which is A B X + (with Colymbus, not with Podiceps). The Heliornithidce appear to be peculiar in the following characters :- (1) The absence of an aftersbaft. (2) The form of the sternum. (3) The shape and relations of the interclavicular \ (4) In the fusion of the pubes with the ischia and the absence of lateral postacetabular ridges. (5) In the arrangement of the intestinal coils. (6) In the form of the biceps cruris. It will be evident therefore, from a glance at the above statement, that the Heliornithidce have more characters peculiar to themselves than characters which ally them with either the Ralline or Colymbine birds ; and these characters appear to m e to be not merely numerous but also for the most part important ones ; nor are they confined 1 I do not emphasize the resemblances which they show in this or other particulars to other groups of birds. |