282 Zoological Society. 



Sect. III. Of Ike Arguments adduced by Professor Owen for believing 

 the Edentata to be allied to Birds. 

 I propose first to enumerate these arguments, and then to consider 

 them more particularly. They are to be found in Professor Owen's 

 interesting papers on the anatomy of the Six-banded and Weasel- 

 headed Armadillos in the Proceedings of the Zoological Society of 

 London, so often referred to and quoted in this paper, and are as 

 follows : — 1. The presence of two caeca in the Dasypus 6-cinctus and 

 Myrmecophaga didactyla. 2. "The gizzard-like structure exhibited 

 in the tendinous external appearance and thickened muscular coat of 

 the stomach of the Dasypodce" and a still nearer approach in the 

 stomach of the Manis. 3. The presence of a similar structure in the 

 Myrmecophagae, accompanied by the habit of swallowing small peb- 

 bles for the purpose of destroying the vitality of the insects which 

 form their food. 4. The similarity of the mucous glands about the 

 os hyoides of the Anteaters to those follicles in the Woodpeckers, 

 which represent amongst Birds the conglomerate salivary glands 

 of the Mammalians ; and the lubrication of the extensile tongue. 

 5. The abnormal number of cervical vertebrae in the Three-toed 

 Sloth. 6. Prof. Owen concludes this line of argument in the fol- 

 lowing words : " The transition is indeed nearly completed by the 

 Monotremata, for of the two genera contained in this order, Echidna 

 presents us with the quills, and Ornithorhynchus with the beak of a 

 bird ; and it is far from being proved that the mode of generation is 

 not the same." 7. The form of the pubis of the Armadillo indicates 

 " that only a small portion of what usually constitutes the symphysis 

 is here joined to its fellow, viz. the anterior angle ;" and in Chlamy- 

 phorus and Myrmecophaga didactyla the ossa pubis remain entirely 

 separate, as is the case in Birds. The pelvis likewise resembles theirs 

 " in the great breadth of the posterior part of the sacrum, the angles 

 of which are anchylosed to the spines of the ischia, and convert the 

 great ischiatic notches into complete foramina." 



1 . The occurrence of double caeca is a remarkable point of affinity 

 to Birds ; but we have previously shown that the presence of caeca is 

 a variable character in the Tortoises, as in both Dasypus and Myr- 

 mecophaga, so that the characters furnished us by this organ seem to 

 approximate them equally to Birds and Reptiles. 



2. We have shown the structure of the stomach in the Tortoises 

 to be gizzard-like. This is also the case in Crocodilus acutus (Owen 

 in Zool. Proc. 1830, p. 139). Hence the stomach of the Edentata 

 presents us with an equal analogy to Reptiles and Birds. 



3. The habit of the Myrmecophaga of swallowing small pebbles 

 to increase the trituration of the gizzard, is certainly analogous to 

 that of the Gallinaceous Birds. But the same has been remarked in 

 the Egyptian Crocodile by Professor Geoffroy St. Hilaire, and in the 

 sharp-nosed species by Prof. Owen (ubi supra). As the gizzard-like 

 structure and pebbles of the Myrmecophaga are adapted to the diges- 

 tion of animal food, as in the Reptilia, and not of vegetable, as in 

 the Gallinaceous Birds, I consider the resemblance of the Edentata 

 in these respects to be greater to the former than the latter animals. 



