GRUIFORMES : RALLIDAE 



243 



Order X. GRUIFORMES. 



The Gruiformes, which lie between the Galliformes and the 

 Charadriiformes, compose a somewhat heterogeneous Order, which 

 inchides forms so different as the RaUidac (Kails), Gruidae 

 (Cranes), Aramidae (Limpkins), Fsophiidae (Trumpeters), Caria- 

 midae (Seriema and Chunia), Otididae (Bustards), Rhinochetidae 

 (Kagu), Enrypygidae (Sun-Bitterns), and Heliornithidae (Fin- 

 foots). Of these a large number are Waders, but the Land- 

 Eail, the Wekas, the Kagu, the Bustards, and others, cannot be 

 classed in this category. All agree in having no true crop, a 

 tracheo-bronchial syrinx, and an elevated hallux ; while the 

 front toes are never completely webbed, though nearly so in 

 Heliornis ; the nares, moreover, are pervious, except in Rhinochetus. 

 In the last-named the condition of the newly-hatched young is 

 unknown, in Heliornis they are said to be naked at first, but in 

 the remainder of the group they are covered with simple down. 

 In structure the nine Families differ widely, a fact which would 

 seem a strong argument against combining them under one head ; 

 but the aggregate of such points must be considered, and in any 

 linear system the relationships within every Order cannot possibly 

 be equally close. The present arrangement does not differ greatly 

 from that adopted by Mr. Sclater, ^ wherein he accepted the 

 names Alectorides and Fulicariae, used by Nitzsch, but made 

 the former to consist of the Aramidae, Etiryfygidae, Gruidae, 

 Psophiidae, Cariarnidae, and Otididae, and the latter of the 

 Rallidae and Heliornithidae. Some writers, both modern and 

 ancient, have placed the Otididae in the Limicoline group. 



Eam. I. Rallidae. — The Eails constitute a somewhat general- 

 ized and very homogeneous Family, found in almost all parts 

 of the world. The body is peculiarly compressed — enabling them 

 to move with ease in dense vegetation — while the keel of the 

 sternum is especially reduced in those flightless forms for which the 

 group is remarkable. The strong bill varies in dimensions, being 

 long in typical Eails, shorter and thicker in Crakes, decidedly curved 

 in HiiiiKiitornis, and reaching its maximum size among the Galli- 

 nules in Porphyrio and JVotornis, where it is subconical. A horny 

 shield is present upon the forehead in Megacrex, Hahroptila, the 

 G-allinules and the Coots, which is usually rounded or truncated 



1 Ihis, 1880, p. 408. 



