AS MEANS OF IDENTIFICATION 573 



sternum double-notched; humerus with a large ectipicondyloid process; cceca vestigial; 

 beak large, with a sharply marked gonys to the lower jaw ; nostrils linear, pervious. 



(a) Genus Sterna. 1 Beak slender, tapering, moderately long ; nostrils pervious ; toes 



semi-pahnated ; tail forked. (Vol. iii. p. 57.) 



(b) Genus Xema. Tail forked ; front toes completely webbed. (Vol. iv. p. 510.) 



(c) Genus Rkodostethia. Tail wedge-shaped ; front toes fully webbed ; hind-toe with 



a largo curved claw. (Vol. iv. p. 511.) 



(d) Genus Larus. Tail square ; front toes fully webbed ; hind-toe small but distinct. 



(Vol. iii. p. 114.) 

 () Genus Rissa. Tail square, slightly forked in the immature bird ; front toes fully 



webbed ; hind-toe vestigial. (Vol. iii. p. 132.) 

 (/) Genus Pagophila. Tail square; front toes fully webbed; hallux joined to inner 



toe by a narrow, serrated membrane ; tibia feathered nearly to the tibio-tarsal 



joint. (Vol. iv. p. 513.) 

 (c/) Genus Stercorarius. 1 Beak with a distinct cere ; sternum with but a single pair of 



notches ; claws large and hooked. (Vol. iii. p. 197.) 



5. FAMILY (EDICNEMID.ffi THICK-KNEES. 



Holorhinal, schizognathous ; nostrils pervious ; hallux wanting ; tail wedge-shaped ; toes 

 webbed at the base ; tarso-metatarsus articulated ; eye very large. 



(a) Genus (Edicnemus. Beak shorter than the head, swollen at the tip ; tail relatively 

 short, not exceeding the length of the head. (Vol. iii. p. 230.) 



6. FAMILY GLAREOLID^E PRATINCOLES. 



Nostrils impervious ; nasal aperture round ; skull holorhinal, schizognathous. 



(a) Genus Glareolas. With functional hallux ; tarso-metatarsus short, wings very long ; 



tail forked ; claw of middle toe pectinated. (Vol. iv. p. 513.) 



(b) Genus Cursorius. Hallux wanting ; legs very long ; middle toes very long, and 



with its claw pectinated ; tarso-metatarsus scutellate in front. (Vol. iv. p. 514.) 



7. FAMILY CHARADRIID^E PLOVERS. 



Skull with basipterygoid processes and occipital fontanelles; nestlings nidifugous, striped 

 or mottled. 



(a) Genus Phalaropus. Feet lobed ; plantar surface of tarso-metatarsus serrated. 



(Vol. iii. p. 251.) 



(b) Genus Scolopax. Beak long, cylindrical, somewhat swollen, soft and sensitive at 



the tip; aperture of the ear seated in advance of the anterior canthus of the 

 eyelid. (Vol. iii. p. 269.) 



(c) Genus Gallinago. Beak as in Scolopax, but the aperture of the ear under the eye. 



(Vol. iii. p. 274.) 



(d) Genus Cliaradrius. 3 Beak short, swollen at the tip; wings long and pointed, llth 

 primary much reduced, 10th the longest in the wing ; inner secondaries elongated. 

 (Vol. iii. p. 321.) 



(e) Genus Vanellus. Beak short, swollen at the tip; wings with a carpal tubercle, 



1 The genera Hydrochelidon, Gelochelidon, and Anoui are not founded on structural characters and hence cannot 

 be recognised. 



2 The genus Stercorarius must include the so-called genus Megalestris. 



3 It is impossible without juggling with facts to recognise the genera Eudromias, jflgialites, Squatarola, which 

 must be included in the genus Charadrius. 



VOL. IV. 4D 



