AKT.,19 CONCERNING birds' TONGUES GARDNER 19 



indented while the whole organ is quite rudimentary. There is no 

 suggestion of aiRnity between these forms and the motmots. 



The hornbills (Bucerotidae) also have rudimentary tongues, al- 

 though they are not without form. Thus in Loplioceros tnelanoleucus 

 (fig. 84) it is flat, slender, and square tipped, while in the huge billed 

 Hydrocorax mindanensis it is rather triangular, fleshy and supplied 

 Avith a few small spines, and this is true also for Dlchoceros bi- 

 cornis. 



Upupidae: The hoopoes have exceptionally small rudimentary 

 tongues which are reduced to a mere triangle of flesh without form 

 or function. 



Such a review shows that a wide range of variation is seen in the 

 suborder Coraciae, with few indications of affinity shown and in 

 many forms a rudimentary structure through loss of function. 



The suborder Striges have tongues very closely resembling those 

 of hawks, a suggestion of affinity that is misleading. 



They are horny tipped and well beset with papillae, while mucous 

 gland pores are abundant, an appearance much like that of the 

 Falconidae and due either to convergent evolution or to the rap- 

 torial diet. There is usually a certain degree of curling and the tip 

 is often somewhat incised. As examples are shown Tyto pratincola 

 (fig. 78), Speotyto cunicularia hypugaea (fig. 76), Otus asio hendire'i 

 (fig. 79), Spiloglaux novae zealandiae (fig. 80), and Asio loilsonianus 

 (fig. 77). The hawk owl {S^irnia ukda, fig. 44) has but one row of 

 spines posteriorly, the reason for which is not apparent. The horned 

 owl {Bubo virgi7iimius) has a broad, flat tongue well covered with 

 spines. 



Suborder Caprimulgi 



In this group, Wetmore ^*^ finds four main types of tongues. First 

 that of Nyctibius^ which he describes as " small in proportion to the 

 mouth cavity as in other Caprimulgi. In form it differs consider- 

 ably from the tongues of related genera. The tip of the tongue in 

 Nyctibius is somewhat elongate, with the lateral outlines at first 

 concave. The postero-lateral margins are produced as elongate 

 points that equal the anterior portion in length. The outline of the 

 lateral margin of these is convex. In general the form of the tongue 

 is that of the head of a spear point, with a deeply incised base, 

 spreading posterior angles, and slender point." He finds the lateral 

 margin supplied with spines and a few minute spines on the upper 

 surface. 



Podargus is described as having an elongate tongue, being " much 

 larger in proportion to the size of the mouth cavity than in other 



^0 Wetmore, A. On the Anatomy of Nyctibius, with Notes on Allied Birds. Proc. 

 U. S. Nat. Mus., vol. 54, pp. 577-586, 1918. 



