508 Letters, Extracts, Notices, 6fC. 



Pt. ventralis (PL I., Pt. coll. lat., Pt.v.). — The anterior 

 end of this tract along its dorsal border has fused with the 

 Pteryla spinalis (PI. I., Pt. coll. lat.). About halfway- 

 down the neck it divides into two, and exchanges its ventral 

 for a lateral course. At the shoulder a branch is sent 

 upwards and backwards to join the humeral tract : the main 

 trunk — the pt. ventralis of the original paper — on the breast, 

 again divides into a strong, narrow, outer, and a broad, but 

 weaker, inner branch, the two being separated by a narrow 

 apterion. The outer branch passes into the pteryla femo- 

 ralis, sending at the same time sharply forward a narrow 

 double row of feathers to join the hypopteron. The inner 

 tract is probably continued down to the anus, but, the bird 

 having been eviscerated, this region is too much disturbed to 

 afford trustworthy data. 



Apt. trunci laterale. — Arising from the side of the neck, 

 rather more than halfway down, it passess backwards, 

 dividing the humeral from the spinal tract ; it then expands 

 into a large space embracing the whole side of the trunk, but 

 divided more or less completely into two portions. The first 

 of these two extends from the summit of the shoulder back- 

 wards to the anterior margin of the femoral tract. The 

 second arises between the two branches of the pteryla ven- 

 tralis ; running backwards between the leg and trunk, it 

 sweeps round the femoral tract, and serves to divide it from 

 the pt. spinalis. The first of these two spaces, as will be 

 seen in PI. I., is more or less completely subdivided by a 

 double row of feathers from the outer branch of the pt. ven- 

 tralis to the hypopteron. 



The following corrections are therefore necessary : — For 

 the description of the p t. spinalis (p. 2), andpt. ventralis 

 (p. 3), and apt. trunci laterale (p. 6), see above. 



Erase the term j!>/. colli lateralis and the text apper- 

 taining thereto on p. 2, and for apt. colli lateralis (p. 9) 

 read apt. trunci laterale. 



PI. I., for Pt.coll.lat. read Pt.v. 



PI. I., for Apt.c.lat. read Apt.t.lat. 



PI. II., for Apt.c.lat. read Apt.t.lat. 



