OR ANIMALS WITH BLOOD. 245 



He states that the Peristeroeide usually lay two eggs, 

 but Phatta and Trijgon generally lay three.* This last 

 statement is incorrect ; there seems to be no record of birds 

 of the pigeon family laying more than two eggs. 



A small group of birds, the Apodes of Aristotle, so called 

 because of their abnormally small or weak feet, includes 

 Chelidon (the swallow), Apous or Kypsellos (the swift and 

 house-martin), and Drepanis (the sand-martin). 



Aristotle gives an important character of Apous or 

 Kypsellos, viz., that its metatarsus is feathered, t but he gives 

 very little information about Drepanis, and Pliny and other 

 ancient writers render no assistance in identifying this bird. 

 The Drepanis, according to Aristotle, is closely allied to 

 Apous, and is seen and caught when it rains in summer, but 

 is a rare bird, on the whole.! 



Belon and Gesner identified Drepanis with the sand- 

 martin, but, during comparatively recent years, there has 

 been an inclination to identify it with the Alpine swift 

 {Cypselus melha). This is not a good identification, and there 

 does not seem to be sufficient reason to abandon Belon and 

 Gesner's conclusion. 



The name Drepanis (from Drepane, a sickle) does not give 

 much assistance ; it may refer to the shape of the wings, 

 and would then favour the identification of Drepanis with 

 the Alpine swift, or it may refer to the long, curved, hind 

 claw of the sand-martin. It seems likely, however, that the 

 Alpine swift, with its very short feet and feathered metatarsus, 

 should be included with the common swift (C. apus), under 

 the name Apous. Again, Aristotle's assertions about Drepanis 

 do not appear to be consistent with the view that it is the 

 Alpine swift, for this bird is very common in Greece, through- 

 out the breeding season, and, according to Von der Miihle, 

 is sold in large quantities in the Grecian markets. § 



The sand-martin, which is somewhat rare in Greece, is 

 said to breed in the banks of the Alpheus and the Eurotas, 

 and to be seen in summer. It would be seen more especially 

 after rains, and its stay in Greece is known to be compara- 

 tively short. All these considerations tend to show that 

 Drepanis is the sand-martin. In his letter, previously 

 referred to, Mr. G. C. Zervos expresses his opinion that 



* H. A. vi. c. 4, s. 1. f Ihid. ix. c. 21, s. 1. 



I Ihid. i. c. 1, 8. 9. 

 § Sharpe and Dresser's Birds of Europe^ 1871-81, vol. 4. Section on 

 Cypselus melba. 



