186y.] PROF. HUXLEY ON THK ALECTOROMORPHyE. 



Fig. 7. 

 Fig. 6. '"^ 



301 



Fig. 6. The dorsal aspect of the pelvis of Gallus domcaticus. 

 7. The dorsal aspect of the pelvis of Tefrao urogallus. 

 (The letters as beibre.) 



In the Tetraonine or Grouse type, on the other hand — 



1. The postacetabular region is very broad (fig. 7, p. 301); the ih'a 

 are truncated nearly opposite the end of the sacrum, and it is the 

 external angle of the posterior edge of the ilium which is rather the 

 longer. 



2. The ulnar and distal edge of the basal phalanx of the second 

 digit is produced ; and the phalanx of the third digit has a strong 

 basal tubercle. 



3. The anterior margin of the deltoid crest is less obHque, and the 

 angle of the crest is sharper and more prominent. 



4. The hypocleidium has straight edges and a triangular form, 

 the apex of the triangle being directed forwards. 



5. The tarso-metatarsus is not half as long as the tibia. 



6. The mandibular foramen is very large. 



The two series of forms meet among the Partridges and Quails — 

 Perdix* lying on the Tetraonine, Caccahis, RoUulus, Francolinus, 

 and Coturnix on the Galline side of the boundary. 



* This has abeady been pointed out by Mr. Parker, " Gallinaceous Birds and 

 Tinamous" (Trans. Zool. Soc. v. p. 155). 



