112 MEMOIRS OF THE CARNEGIE MUSEUM 



©f Penguins and Gannets have thus perished. Superficially a Booby is distinguished 

 from a Gannet in that the former lacks the median stripe of naked skin over the re- 

 gion of the throat, so characteristic of the latter birds. As a rule, too, Boobies are 

 tropical species, and breed in trees, and are of wide distribution. 



Morphologically, the genus Anhinga has received more attention than any other 

 of the Steganopods. " Beside the excellent description of the American bird's ali- 

 mentary canal furnished to Audubon by Macgillivray, other important points in its 

 structure have been well set forth b}^ Garrod and Forbes in the Zoological Proceed- 

 ings (1876, pp. 335-345, pis. XXVI.-XXXIII. ; 1878, pp. 679-681 ; and 1882, pp. 

 208-212), showing among other things that there is an appreciable anatomical dif- 

 ference between the species of the New World and of the Old ; while the osteology 

 of P. melanog aster has been admirably described and illustrated by Professor Milne- 

 Edwards in M. Grandidier's great Oiseaux cle Madagascar (pp. 691-695, pis. 284-285). 

 In all the species the neck affords a feature which seems to be unique. The first seven 

 of the cervical vertebrae form a continuous curve with its concavit}^ forward, but the 

 eighth articulates with the seventh nearly at a right angle, and, when the bird is at 

 rest, lies horizontally. The ninth is directed downwards almost as abruptly, and those 

 which succeed present a gentle forward convexity. The muscles moving this curi- 

 ous framework are as curiously specialized, and the result of the whole piece of 

 mechanism is to enable the bird to spear with facility its fishy prey." (Newton, Arts 

 "Gannet," and "Snake-Bird," he. cit., p. 188. 



Again we find the same eminent ornithologist under the article " Frigate-Bird " * 

 declaring that that interesting Steganopod "was placed by Linnaeus in the genus Pel- 

 ecanus, and until lately its assignment to the family Pelecanidx has hardly ever been 

 doubted. Professor Mivart has, however, now declared [Trans. Zool. Soc, X., p. 

 364) that, as regards the postcranial part of its axial skeleton, he cannot detect suf- 

 ficiently good characters to unite it with that family in the group named by Pro- 

 fessor Brandt Steganopodes. There seems to be no ground for disputing this 

 decision so far as separating the genus Fregata from the Pelecanidse goes, but sys- 

 tematists will probably pause before they proceed to abolish the Steganopodes, and 

 the result will most likely be that the Frigate-Birds will be considered to form a 

 distinct family {Fregatidx) in that group. In one very remarkable way the oste- 

 ology of Fregata differs from that of all other birds known. The furcula coalesces 

 firmly at its symphysis with the carina of the sternum, and also with the coracoids 



* " ' Man-of-War Bird ' is also sometimes applied to it, and is perhaps the older name, but is less distinctive, some 

 of the larger Albatrosses being so called, and, in books at least, has generally passed out of use." [Man-o'-war Bird is 

 the vernacular name given to this species in the A. O U. Check-list of North American Birds, and is the one in com- 

 mon use by ornithologists in the United States.] 



