766 THE POPULAR SCIENCE MONTHLY. 



curious, generalized type, the Dromas ardeola, that web-footed, 

 long-legged, black and white bird found on the shores and some 

 of the islands of the Indian Ocean. At different times ornitholo- 

 gists have placed this form not only in various families, but in 

 various orders. It has even been associated with the terns, and 

 Sharpe has said it "is in habits a plover, in many points of struc- 

 ture larine [gull], but it burrows in the sand and lays a white Qg^, 

 like that of a j^etrel surely a combination of characters which 

 demand that it shall have a sex)arate rank as the representative 

 of a definite suborder." British ornithologists call it the " cava- 

 lier," and place it near the stilts. 



Again, we have the " pratincoles," all of the single genus Ola- 

 reola, which are curious little ploverlike birds which have a flight 

 resembling that of the swallows, and, like them, they feed upon 

 the wing. There are nine or ten species of these, being found in 

 Europe, Asia, Africa, and even Australia. They are distinguished 

 for their trim build and marked delicacy in the coloration of 

 their plumage. They nest upon the ground.* With the gull 

 group, the plovers are beautifully linked by those very types of 

 outliers, the sheathbills of the genus Chionis. Among the limic- 

 oline birds their nearest allies are seen to be the oyster catchers,! 

 while their structure goes to show that, besides the gulls, they 

 have affinities with a number of other groups. Sheathbills are of 

 great interest to the ornithologist, as they are undoubtedly the 

 descendants of very ancient and generalized types. There are at 

 present only two species of them known the one, C. minor, from 

 the Kerguelen Islands, and the other, C. alba, from some of the 

 islands of the antarctic seas. In life they somewhat resemble 

 pigeons, and both species are pure white in plumage, while they 

 receive their English name from the little saddle of horn en- 

 sheathing the base of the upper part of the bill. Numbers of 

 their eggs have been taken, and they are said to resemble those 

 of a plover. Chionis lives upon shellfish and certain sea weeds, 

 and some authorities aver that they have been known to eat the 

 eggs of other birds. Unanimity of opinion among naturalists as 

 to their systematic position as yet by no means exists, and a thor- 

 ough examination of their anatomy is still a thing much to be 

 desired. J 



Returning once more to the neighborhood of the rails and 



* Some of our best systematists believe they connect the plovers ( L'miirola') with the 

 irranes that is, the true Charmlrii through the coursers, the thickknees (Oi.'(/lcncmi), and 

 the bustards (Otis), f Hmmaiopus. 



% As other avian outliers, and in some ways related to the sheathbills, we have those 

 curious South American forms bclonj^ing to the p;cn('ra TJiiuororis and Af/(i(/i.s of the fam- 

 ily 'Jliinocoridw. Our space will only j)ermit of our meiitiouiug their names here. 



