564 rTERYLOGRAPHY OF GOAT-SUCKEBS AND OWLS—CLABE. voL.x\ai. 



part of the breast, and chiefly the complete separation on the breast 

 of the sternal and ventral tracts, all make up the typical pterylosis of 

 the owls and are clearly shown in figs. 9 and 10. Asia unhoniamis 

 does not show t^iese points as well, or at least the specimens which I 

 was able to obtain did not show them, but as they were not in very 

 good condition it is possible that perfect material will show more com- 

 plete agreement with Asio accipitrinus. The species of wilsonianus 

 examined did not show clearly the longitudinal arrangement of 

 feathers on the crown, although the head was not uniformly feathered 

 as in Sjjeotyto; the femoral tract was no longer a true femoral, but 

 scarcely reached the femur at all, being confined to the back of the 

 tibia (this may be easily understood by imagining the femoral tract in 

 fig. 10 to be moved down on the tibia one-eighth of an inch nearer the 

 tarsus); on the front of the tibia the feathering was so very dense that 

 there was a very distinct tract there. The two species agreed in pos- 

 session of fifteen secondaries and in the following formula for the prima- 

 ries: 9, 8, 7, 10 = 0, 5, 4, 3, 2, 1, U. 



S}i ec i ni e n s era m i n cd. 



Nitzsch says of Strix hrachyotus: "Twenty- four remiges, the second 

 the longest, the first somewhat shorter than the third." Making the 

 same addition and reversion as we found necessary under Speotyto, this 

 formula becomes 9, 8, 10, 7, G, 5, 4, 3, 2, 1, 11, which is almost the same 

 as that I have given. He only credits the genus with fourteen second- 

 aries, while I have always found one more. 



Genus M E G A S C O P S . 



Except for the peculiar difference in the arrangement of the longi- 

 tudinal rows on the head, the pterylosis of this genus is very much 



like that of Asio. This difference is very 

 Avell shown in the plates and may be briefly 

 characterized thus : In Asio the longitudi- 

 nal rows are central, while in Megascops 

 they are lateral. On the infra-mandibular 

 space the feathers are more numerous in 

 the screech owls, but other distinctions are 

 not obvious. There are fourteen second- 

 aries, and the eleven primaries rank as fol- 

 lows: 7=6, 8, 5, 9, 4, 3, 2, 10=1, 11. The 

 feet were more heavily clothed in feathers, though the same surface was 



Fifi. n. 



HEAD OF MEGASCOPS ASTO. 



rraiigement of Iorigitudin.il row 



