324 NATURAL HISTORY. OF BIRDS. 



The question of the division of the owls into sub-families is one which has long 

 perplexed ornithologists. The group has seemed so homogeneous that good charac- 

 ters on which to found subdivisions were hard to find, and even now it would be pre- 

 mature to say that any unquestionable arrangement has been effected. Over forty 

 years ago Nitsch showed that the feathering (pterylography) of the barn-owl or 

 screech-owl, Aluco flammeus, was very different from that of all other members of 

 the family, and some peculiar osteological characters were also found to exist in the 

 same bird. On these discoveries as a basis, two sub-families were formed, and a few 

 years ago there was a general feeling among systematists that at last the question was 

 nearly settled, and they might safely place the barn-owls and their allies less than 

 half a dozen species in all in one group; and all the remaining hundred species or 

 more in a second. . One species, however, Phodilus badius, which had been placed in 

 the smaller group, has now been found by Alphonse Milne-Edwards to combine the 

 peculiarities of both groups, and thus to be a true connecting-link between them. 



It seems impossible to include Phodilus in either group, yet systematists are re- 

 luctant to allow it to stand by itself as the type of a new sub-family, and equally 

 reluctant to unite all owls into a single group, only subdividing them into genera and 

 species. Under these circumstances, and especially while new species are still being 

 discovered, most ornithologists are inclined to wait for a time, and not commit them- 

 selves. The two main groups alluded to may be thus characterized : 



" Sub-family Aluooninae. Barn-owls and their allies. Sternum without manubrium 

 and entire (i. e., un-notched) behind; clavicles united together, forming a furcula, and 

 solidly joined to the keel of the sternum ; tarsus without a bony ring or arch over the 

 extensor tendon of the toes ; claw of the middle toe with its inner margin serrate. 



J O 



Sub-family Striginas. Other owls (except Phodilus). Sternum with a distinct 

 manubrium, and with two or more clefts or notches in the hinder margin : clavicles 



o y 



never united to the keel of the sternum, often not even united to each other ; tarsus 

 with a bony ring or arch over the groove, in which lies the common extensor tendon 

 of the toes ; inner margin of middle claw not serrate. 



Phodilus, or Photodilus as it is also written, agrees with the Aluconinoe in want- 

 ing the manubrial process of the sternum as well as the bony arch on the tarsus, but 

 differs from them and agrees with the Striginre in having the hinder 

 margin of the sternum distinctly notched, while the clavicles are neither 

 united to each other, nor to the keel of the sternum. 



The burrowing-owl, Speotyto cunicularia, is one of the most pecu- 

 liar forms which we meet with among the owls, and, although too 



FIG. 150. - Bill of ,, , , -. , . . 



Speotyto, show- well known to warrant extended description, we can hardly pass it 

 without calling attention to its long slender legs, imperfect facial 

 disk, and terrestrial habits. It is about nine and a half inches long, the tail however, 

 being rather short, only three to three and a half inches. The colors are brown 

 and yellowish-white in about equal proportion, the upper parts being brown with very 

 numerous roundish white spots, while the under parts, wings, and tail are barred with 

 brown and white. The sexes are alike in size and color. It is peculiar to America, 

 where it occurs abundantly in some places, especially on the pampas and adjacent lands 

 of South America, and the plains of the western United States. On the west coast 

 of North America it extends northward to the Columbia River, while on the east coast 

 a few isolated colonies are found in Florida, and it occurs abundantly in Texas. On 

 the island of Guadeloupe, in the West Indies, a form is found which has sometimes 



