508 AEKIV FÖR ZOOLOGI. BAND 1. 



Ibis has no mentale but the medial suture between the lateral 

 shields (infralabials) extends to the tip and there is no sub- 

 division of these lateral shields on the mandibular ramns, 

 whereas in the Curlew as well a terminal mentale is present 

 as also two longitudinal shields on either ramus. 



The bilis of the other Limicolce may more or less easily 

 be referred to the type exhibited by Charadriidce as modifica- 

 tions of the same. The bill of Oedicnemus is only a strength- 

 ened Charadrius-hill suiting a somewhat larger bird which 

 sometimes attacks other prey than beetles and other insects. 

 In the »Seedsnipes» (Thinocorys) the diet of which is made 

 known by the name, the bill is strongly shortened in conse- 

 quence of the graminivorous habit and it has assumed almost 

 the same shape as in Galliformes, rostrale and mentale being 

 best developed, but basally remnants of the other elements 

 may be recognized. 



The bill of the Auks (AIccb) contain the same elements 

 as that of the Gulls (Lari), although as a rule rostrale is 

 less defined in the former than in Stercorarius and Larus. 

 The side of the upper rhamphotheca is formed by a labial 

 which in Uria is rather well defined. In the same genus 

 the limits of the infralabial and the submandibular at the 

 base of the lower rhamphotheca are well conspicuous especi- 

 ally in U. grylle (L.). In U. lomvia (L.) = (brunnichi auct.) 

 and U. troille (L.) the submandibular is rather short. In 

 Alea and the short-billed Simorhynchus the feathering extends 

 still further forward and then the submandibular seems to 

 be fully reduced, but this is plainly secondary. The inter- 

 nasal and nasal träets are more or less overgrown by feathers 

 in most Auks. 



The much metamorphosed bilis of the Pufnns are more 

 difncult to analyse but contain probably the same elements 

 as in Alca. 



In the Cohimbce the tips of both mandibles are härd 

 and this is effected by the development of the rostrale and 

 mentale respectively. In the fruit-eating pigeons these 

 parts need to be stronger than in those which only use 

 their bill as a pair of pincers with which they pick grains 

 and seeds. In correspondence with this the former have 

 rostrale and mentale of their bilis larger and harder so that 

 they are able to attack their food in an effective manner. 



