623 



Order XX. IMPENNES.* 



(By W. R. OGILVIE-GRANT.) 



Beak never hooked ; nares pervious, holorhinal ; no basipterygoid 

 processes ; palate schizognathous ; vomer blade-shaped, paired, the 

 two halves united along the antero-ventral border ; palatines broad 

 and flattened posteriorly ; pterygoids expanded into flattened 

 lamina distally, never rod-like ; iuterorbital septum perforate ; with 

 deep supraorbital grooves ; lachrymals free, never contributing to 

 form the supraorbital grooves, and without conspicuous lateral 

 wings when the skull is viewed dorsally, its lower limb pedate, 

 articulating with the quadra to-jugal bar ; masillo-palatiue processes 

 in the form of slender curved rods, never laminate. 



Sternum half as broad as it is long, with a pair of notches 

 posteriorly, a spina externa, and with the keel projecting forward 

 beyond the corpus sterni ; pre-coracoid and acro-coracoid large ; 

 scapula of great breadth and truncate posteriorly. 



All the bones of the pectoral limb much flattened dorso-ventrally ; 

 humerus with a large non-pneumatic fossa at its proximal end ; 

 obliquely truncate distally and grooved for large, ossified sesamoids ; 

 ulnare of great size, and more or less triangular in outline ; first 

 and second metacarpals indistinguishably fused with one another 

 and the former without phalanges. 



Pelvic limb with the tarso-metatarsus nearly as broad as long. 

 Metatarsals more or less completely separated one from the other by 

 grooves ; no ecto-trochlear foramen ; ii. trochlea shorter than the 

 III. and not directed backwards. (TF. P. Pycraft.) 



* The following papers refer to the anatomy etc. 'of the group : — Reid, P. Z. S. 

 1835, p. 132 [anatomy of A. patagonica] ; Braudt. M6m. Acad St. Petersb. 

 (6) V. pt. ii. pp. 164, 213-217, pis. xii., xiii. (1839) [osteology]; Huxley, 

 P.Z. S. 1867, p. 458; Coues, Pr. Boat. Soc. xiv. pp. 251-253 (1872); Hyatt, 

 Pr. Bost. Soc. xiv. pp. 238-241 (1872) ; Gairod, P. Z. S. 1873, p. 470 [carotids 

 present], p. 642 [muscles], 1875, p. 348 [plautar tendons] ; Gervais & Alis, 

 Journ. Zool. vi. pp. 424-472, pis. xvi., xvii. (1877) [osteology and myology] ; 

 JuUien, Bull. Soc. Z. Fr. iv. pp. 374-382, pis. viii., ix. (1879) [anatomy of 

 A. patagonica] ; M. -Edwards, Ann. Sci. Nat. (6) ix. Ai-t. 9, pp. 1-82, pis. 17-20, 

 and map of distribution (1880); Filhol, Bull. Soc. Philom. {!) vi. p. 226 

 (1882) [osteology], vii. p. 9293 (1883) [circulatory system, muscles] ; Nathusius, 

 J. f. 0. 1882, p. 293 [egg-shell of Sphcniscus] ; Watson, Voy. Chall. vii. pp. 1- 

 243, pis. i.-sis. (1883) ; Beddard, P. Z. S. 1885, p. 843 [visceral anatomy] ; 

 Sclater, Ibis, 1887, p. 367 ; Menzbier, Bull. Mosc. 1887, pp. 483-587, pi. vin. 

 [osteology] ; Beddard, P. Z. S. 1888, pp. 252-258 [visceral anatomy] ; Gadow, 

 P. Z. S. 1888, p. 665 [development of remiges] ; Berkessy, MT. orn. Ver. Wien, 

 1891, pp. 22, 23, 45, 46, 87, 88, 118, 119; Mitchell, P. Z. S. 1896, p. 142 

 [intestinal tract]. 



