SOME OF THE OUTLIERS AMONG BIRDS. 763 



types, the student will there be confronted with at least two fami- 

 lies, the exact position of either of which has more or less puzzled 

 the ornithologist I refer to the megapodes * and those curious 

 little quail-like birds the hemipodes or "button quails." The 

 former leave their eggs to be hatched without incubation, simply- 

 burying them in the ground as many reptiles do, or heaping over 

 them a mound composed of leaves, earth, and other materials. 

 There are several species and genera, and the chicks of all are 

 highly developed at birth. f Again, these gallinaceous types, or 

 the " fowls " or " chicken types," | including as they do everything 

 after the fowl order, as turkeys, pheasants, quails, peacocks, and 

 a perfect host of related kin, are beautifully linked with the 

 pigeons * through the true intermediate forms the sand grouse. || 



The sand grouse are small, columbo-partridge forms given to 

 remarkable erratic migrations over certain parts of Europe and 

 Asia. Related to the pigeons we have the extinct dodo, and the 

 nearly extinct "tooth-billed pigeon" of the Samoan Islands {Di- 

 dunculus strigirostris). Other birds possessing galline affinities 

 are the well-known curassows,"^ and they in their general appear- 

 ance somewhat remind us of the curious " hoactzin," !) one of the 

 veriest " outliers " among birds in existence. 



Even at the present writing, avian taxonomers are by no 

 means agreed upon the question of the exact relationships of this 

 bird. Buffon placed it among the curassows, while Gmelin and 

 others arrayed it with the pheasants. % Early in this century 

 Illiger created for it the genus it now occupies, since which time 

 it has received the closest possible attention from ornithotomists 

 in various parts of the world. % 



Opisthocomus has a size about equal to the chachalaca of our 

 Texan border, and is extremely remarkable in its anatomy, its 

 appearance, its nesting, and its habits. It is found in tropical 

 South America, and but the one species of it is at present known. 



* Megapodiidce. 



f Huxley made an iadependent group for the hemipodes ( Turnicomorphce), but other 

 authors still retain them with the galline birds as the Turnicidce. The first-named great 

 authority is probably correct in his position in this matter, or, if retained among the galli- 

 naceous types, they are at least entitled to superfaniily rank. 



:j; Gallince. * Columhce. 



II Fterodes, Syrrhapics, to Gcophapes. ^ Graces. 



() Opisthocomus cristatus. J Phaxianns. 



I According to Newton, who, referring to Huxley's and Ganod's opinion, " Opisthoco- 

 mus must have left the parent stem very shortly before the true Gallince first appeared, and 

 at about the same time as the independent pedigree of the Cuculidie and Muxopkar/idw 

 commenced, these two groups being, he believed [Garrod], very closely related, and Opisthoco- 

 mics serving to fill the gap between them." This quotation is from Newton's A Diction- 

 ary of Birds, a work now passing through the press. The figure of the hoactzin herewith 

 presented, and drawn by the present writer, is also from the same excellent work. 



