70 PTERYLOGRAPHY. 



the second as the fourth ; the third not much longer, but the longest, The twenty-sixth is placed 

 at the elbow. The pollex has no nail. 



B. With the scapular portion of the spinal tract briefly cleft. 



The division of this part is, indeed, usually perceptible, but is constantly shorter than half 

 the distance of the extremities of the fork from the end of the neck. Frequently there is some 

 trouble in detecting any furcation at all. The dorsal portion is always united with the fork by 

 two convergent rows of single feathers. In the other characters the pterylosis differs in no 

 respect from that described for S. bubo and S. alum ; even the lumbar tract is present. 



a. With a tolerably distinct fork. 



1. Str. nisoria. Twenty -four remiges ; the first as long as the sixth; the second interme- 

 diate between the fourth and fifth ; the third somewhat longer than the fourth ; the first three 

 with an emargination situated near the apex. 



2. Str. cunicularia TEMM., PI. Col., "146. In all respects like the preceding species, 

 except that the first primary is equal to the fifth, and is the only one that has an emargination. 



3. Str. pygmcea BECHST. Exactly like the two preceding species. The remiges, like the 

 whole plumage, were in course of moulting in the specimen examined ; their proportions were 

 consequently not determinable. 



b. With a scarcely perceptible fork. 



4. Str. passerina BECHST. Twenty-four or twenty-Jive remiges ; the first as long as the 

 fifth or sixth ; the third and fourth the longest, especially the latter ; the first four with a distinct 

 emargination, and the second to the fourth with a corresponding diminution of the outer 

 vane. 



5. Str. dasypus BECHST. Pterylosis remarkably delicate ; that is to say, the tracts are very 

 narrow in all parts. Scapular portion almost undivided. Twenty-three remiges ; the first two 

 with a strong eraargination near the apex ; the first equal to the eighth, the second to the fifth, 

 and the third the longest. 



6. Str. pumila TEMM., PI. Col., 39. Tracts exactly as in the preceding species. Twenty- 

 Jive remiges ; the first two with a slight, deeply seated emargination ; the first shortest of all the 

 primaries ; the second equal to the seventh, the third to the fifth, and the fourth very little 

 longer than either of the latter. 



II. Owls in which the outer branch of the inferior tract returns into the stem posteriorly. 



The DISK-OWLS (Str.Jlammea LINN., Str.pcrlata LIGHT., Str.furcata TEMM., and Str.badia 

 TEMM.) belonging to this group are in every respect so peculiarly organized and so different 

 from the other Owls that I must attribute to them the rank of a distinct genus, for which I 



