4 o2 SCIENCE PROGRESS. 



made since Marsh's discovery of the Toothed birds of 

 North America. In this case Patagonia, a region long 

 known for the wealth and peculiar character of its fossil 

 Mammalia, has yielded a number of the most extraordinary 

 avian types yet known. The discovery of these is due 

 to Dr. F. Ameghino and his brother, to the former of 

 whom we are indebted for the most complete account of 

 them that has yet been published. 



The first mention of the existence of gigantic extinct 

 birds in Patagonia occurs in a letter from Carlos Ameghino, 

 published in the Revista Argentina de Histoida Natural, 

 April, 1 89 1, and containing a report of the results of his 

 collecting expedition in Patagonia. 



Some years before this (in 1887) F. Ameghino (6) had 

 described under the name Phororhacos longissimus the 

 symphysial portion of a large mandible which he considered 

 to belong to an edentate mammal ; a portion of a cranium, 

 the type of the genus Tolmodzts, was also referred to 

 a member of the same class. In 1891, however, thanks to 

 the new and better material obtained by his brother, he 

 was able to show clearly (7) that both these specimens were 

 in fact portions of the skeletons of gigantic birds, and to 

 give a fairly complete diagnosis of the genus Phororhacos. 

 In some points, as for instance in the statement that teeth were 

 present, and that there was a bony helmet-like crest on the 

 skull, this diagnosis, as Ameghino himself afterwards showed, 

 is not quite correct; but it was the first definite statement 

 of the chief characters of these extinct birds. The mandible 

 was shown to be of enormous size and to curve upwards 

 at its anterior end in a manner almost unique among birds ; 

 for though Psophia and Dicholophus were compared with 

 it in this respect, they do not in fact possess this character. 

 The upper mandible forms a strong hooked beak like that 

 of a raptorial bird. 



In the same year ( 1S91) Moreno and Mercerat pub- 

 lished a catalogue of the fossil bird remains in the La 

 Plata Museum (8). This was illustrated by a large series 

 of very beautiful photographic plates, but unfortunately 

 these were unaccompanied by any adequate description of 



