1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 559 



In regard to the differences in the dorsal tract as above given 

 between C. virginianus and C. iexensis, it is probable that an examina- 

 tion of fresh material, which it Avas impossible for me to obtain, will 

 vshow that they are not so great as I have indicated. Indeed, it is 

 likely that good specimens of C. texensis will show dorsal tracts similar 

 to G. virginianus, as Dr. Shufeldt fonnd them so in the specimens 

 which he examined.* 



STRIGES. 



In his System des Pterylographie, Nitzsch has given an acconnt 

 of the pterylography of some 21 species of owls, of which at least 

 live are American, namely: Strix virglniana (Bubo virginianus), S. bra- 

 chyotus {Asio accipitrimis), S. asio {Megascops asio), tS. nyctea {Nyctea 

 nyctea), and S. ennioularia {Speofyto ciiuiciilaria). Besides these, >'. 

 lapponica is closely allied to onr Scotiaptex cinerea and Hybris Jiam- 

 mca is represented in onr Strix praUncola. Aside from Nitzsch's work 

 the only contribution to the pterylography of the owls which I have 

 found is contained in some ''Xotes on the Anatomy of Sj)eotyto cuui- 

 cularia hypogiea" by Dr. Shufeldt, t in which is given a very complete 

 and accurate account of the pterylosis of the burrowing owl; important 

 differences between thaf form and the other owls being pointed out. 

 As a rule, however, it may be safely said that the owls show a striking- 

 uniformity in the arrangement of the feathers, of which the general 

 plan is as follows : The head is more or less fully feathered above, and 

 especially densely in front. The upper cervical tract usually com- 

 mences broad, but rapidly becomes narrow, and forks between the 

 shoulders more or less deeply. The dorsal tract is very incomplete 

 anteriorly and is only indistinctly counected with the cervical forks, 

 but ijosteriorly it becomes a strong single band, which forks behind 

 so as to more or less surround the oil gland. The humeral tracts are 

 strong and usually broad and the parapterum is very evident. There 

 are two complete rows of primary coverts, and on the forearm there are 

 seven or eight rows of feathers, of which the lower three or f<mr are true 

 secondary coverts. The femoral tract is very strong and evident, run- 

 ning obliquely across the upper end of the tibia from the knee, along on 

 the posterior edge of the femur. The tibia and tarsus are usually very 

 completely covered with feathers, and often the toes also. At the base of 

 the gouys the infra-mandibular region is very thickly feathered, but this 

 dense patch divides abruptly and either i)asses up on each side and runs 

 along the ear-conch, as in those owls in which this conch is fully devel- 

 oped, or, as in other species, disappears on the rami of the lower jaw. 

 The rest of the chin and throat are very sparsely feathered in most owls, 

 but in others it is fully covered. The lower cervical tract is narrow and 

 is divided on the neck so as to pass down on either side to foi m the strong 

 sternals. It is also connected with the humerals, and especially with the 



*Jour. Linn. Soc, xx, ji. 341. 

 t Jour, of Morph., June, 1889. 



