FOSSIL VERTEBRATES. 



427 



same time suggesting the possibility of there having been remains 

 of more than these two species of swan in the Zebbug Cave. 



A few specimens in the British Museum Collection are said 

 by Lyclekker* to "indicate a swan of considerably smaller size 

 than C. inusicitsy None of the remains in the present collection 

 agrees with these last, and only one phalanx is somewhat doubt- 

 fully referred to G.falconeri. A left femur wanting the inner 

 condyle agi^ees very closely in size and form with the coiTe- 

 sponding bone of G. musicus (Brit. Mus. 449 d), and there seems 

 little doubt that it ought to be referred to this species, which has 

 already been recorded from Malta both in a fossil state and as an 

 accidental visitor during severe winters. 



The present collection from the Har Dalam Cavern includes a 

 few remains of an anserine bird, believed to be a small swan, 

 which it has been impossible to identify with the corresponding 

 bones of any of the species with which I have been able to com- 

 pare them, either from Malta or among the recent skeletons in 

 the osteological collection of the British Museum. With the 

 small amount of material available it cannot be said definitely 

 that these specimens all represent a single species, but it is 

 believed that this is so at any rate in the case of a proximal 

 portion of a left hiimerus, a right coi'acoid, and a right 

 metacarpus. Besides these, the proximal portions of two ulnae 

 and perhaps a radius might also be included. It is suggested 

 that this species be known as 



Cygnus equitum, sp. n. 



Right metacarpus (text-fig. 1). — It is proposed to take this 

 specimen as the type. It is in a good state of preservation, 

 but has the distal extremity abraded and the central portion of 

 the third metacarpal is absent. It is peculiarly interesting on 

 account of its being relatively very much shorter and stouter 

 than the corresponding bone of any recent species of swan or 

 goose with which I have been able to compare it. This character 

 seems to indicate without much doubt that it belonged to a bird 

 in which tlie power of flight was already considerably reduced. 



The following measvirements, given in millimetres, will show 

 the comparative size of this bone in the Maltese bird, in two 

 recent species of swan, and in Tachyeres. 



* Cat. Foss. Birds in Brit. Mus. 1891, p. 110. 



