E. LÖNNBERG, ON THE RHAMPHOTHECA OF BIRDS. 



493 



superficial and has no real foundation, so that the bill of 

 the Tubinares may be said to be of a uniform, in the diffe- 

 rent families only slightly modified type. But the condition 

 found in the lower rhamphotheca of the Albatrosses with its 

 to one so completely soldered infralabial and submandibular 

 is very important and instructive for the right understanding 

 of the compound bilis of birds. It teaches us that in some 

 cases a great weight may with full right be laid upon a 

 groove or on a feathered strip extending on the bill in a 

 place where it is likely that it indicates a våning division 

 between two shields, and thanks to the bill of Albatrosses 

 compared with that of the Puffinidce many a conclusion may 

 be drawn which otherwise would have been rather böld. 



Among the Steganopodes the compound rhamphotheca and 

 its different pieces is very well developed. In the common 



The bill of Phalacrocorax corho. 



Cormorant (Phalacrocorax carbo) there is a strong, hookshaped 

 rostrale and behind the same a long continuous culminicorn 

 representing an internasdle. In consequence of the reduction 

 of the nostrils there are no nasals to be seen. The maxillary 

 margin is formed by a very long first labial extending from 

 the rostral nearly to the end of the culmen, and behind this 

 one or two (or sometimes even three) smaller labials, which 

 are very well defined and have a most reptilian aspect. The 

 rhamphotheca of the lower jaw has almost the same appear- 

 ance as that of Diomedea and the pieces have quite a similar 

 situation as in the albatross. There are thus to be found 

 an unpaired mentale on the lower side of the end of the 

 mandible, a short but strong first infralabial forming the 

 sides of the distal end and a long second infralabial on either 

 side covering each mandibular ramus behind the symphyseal 



