588 AVEs. 



Rhynchops /awVos^rw.— Yellow-Billed Cut- Water. Plate xlii*. fig. 3. 

 Head, back, and wings, dusky-brown; a longitudinal wliite stripe along the 

 wings ; other parts of the plumage white ; bill and legs yellow. Eighteen 

 inches long. Inhabits Senegal- 



Genus 4.— STERNA.— iinnteiw. 



Generic Character. — Bill as long as the head, longer in some species, near- 

 ly straight, strong, and tapering; mandibles with sharp edges, equal in 

 length, the upper one a little inclined towards the point ; nostrils longitudi- 

 nal, pervious, situated in the middle of the bill ; legs short ; tibia partly nak- 

 ed ; tarsus short, three anterior toes connected by a membrane ; hallux 

 short, placed high on the tarsus ; tail forked ; wings long and pointed, first 

 quill the longest. 



Sterna Dougallii.— The Roseate Tern. Plate xlv. fig. 6. Front, crown, 

 and back of the neck, black ; back, wings, and tail, silver-gray ; breast of a 

 rosy hue ; bill and legs orange ; two middle tail-feathers long, forked, and 

 narrow. Sixteen inches long. Inhabits Europe. 



Genus 5. — I,ARUS. — LimUBUS. 



Generic Character.— S\\\ long, or medium size, strong, hard, compressed, 

 somewhat inflated towards the point, and bent at the tip ; under mandible 

 abruptly angulated near the point ; nostrils lateral, longitudinally cleft, ob. 

 long, pervious, and situated near the middle of the bill ; legs of medium 

 length ; tibia partly naked ; tarsus long ; three anterior toes connected by 

 webs to tlieir tips ; hallux short, articulated a little higher than the toes ; 

 tail-feathers of equal length ; wings long, first and second quills longest. 



Larus Sabini — Sabines Gull. Plate xlv. fig. 7. Head, neck, throat, and 

 lower half of the bill, lead-coloured gray ; wings, back, and tail-coverts, sil- 

 ver-gray ; under parts grayish-white ; gray of the neck with aband of black 

 encircling the neck ; quills black, barred with white ; irides black ; tip of 

 bill cream-yellow ; legs dark gray. Fifteen inches long. Inhabits Green- 

 land. 



Genus 6.— LESTRIS.— /«zg-er. 



Generic Character. — Bill of medium size, hard, strong, cylindrical, some- 

 what tumid towards the point, and slightly hooked at tip ; upper mandible 

 covered at its base by a cere ; the lower one angulated ; nostrils linear, la- 

 teral, situated in the middle of the bUl ; tibia partir.lly naked ; tarsus long ; 

 the three anterior toes completely connected by webs ; hallux very short, and 

 highly articulated on the tarsus; claws considerably hooked; tail some- 

 what rounded ; wings long, first and second quills longest. 



Lestris catarractes. — Brown Squa Gull. Plate xlv. fig. 9. Deep brown 

 above, edged with dull rusty ; under parts same colour, but lighter; head 

 and throat mixed with gray ; bill dusky ; legs and toes scaly-black. Twenty- 

 one inches long. Inhabits the North Seas. 



Genus!.— FROCELL, ARIA.— LinncEus. 



Generic Cliaracter. — Bill broad, and laterally compressed at the base; 

 point compressed and arched ; both mandibles grooved and abruptly inflected 

 towards their points ; nostrils prominent, placed at the surface of the bill^ 



