452 



Vertehrata. 



Tte young ones 

 ai-e covered at 

 first witli a thick 

 coat of down. 



The young ones 

 on hatching are 

 almost naked 

 and very help- 

 less. 



Synopsis oe the Oedees of Aves.* 



1. Saururse: caudal region of vertebral 

 column longer than ti-unk; teeth present. 



2. Odontornithes: caudal region shorter 

 than trunk ; teeth present. 



3. BatitsB: wings not functional; pedes 

 cnrsorii. 



4. Rasores: short, slightly-curved beak; 

 pedes gradarii ; wing short and cui-ved. 



5. Natatores: pedes palmati.f 



6. Grallatores: pedes vadantes. 



7. Raptatores: beak powerful and hooked;' 

 pedes insidentes. 



8. Osoines: pedes fissi, ambulatorii, ad- 

 hamantes. 



9. Clamatores: pedes adhamantes, am- 

 bulatorii, fissi or gressorii. 



10. Scansores: pedes scansorii. 



Hind toe 

 usually 

 small. 



Hind toe 

 usually 

 well-de- 

 veloped 



Order 1. SaururaB. 



Of this order only a single species is known, Archceopteryx litho- 

 graphica, from the Jurassic (lithographic slates). Archseopteryx, 



Fig. 378. Archceopteryx. 1 — 3 first to third fingers, 1' first, 4' fourth toe, fi fibula, 

 il ilium, mc^ first, me, third metacarpal, n naree, o orbit, r cervical rib, ra radius, u ulna, 

 X is possibly a joint, but perhaps due to injury (according to the second interpretation the 

 third finger has three joints, according to the former, four). — Orig. (with the use of figures 

 by Dames). 



* The systematic arrangement of Aves offers considerable dificulties, on account 

 of their great uniformity ; several of the orders given here are not natural groups. 



f For the significance of these terms, see the descriptions of the various orders. 



