100 PTERYLOGRAPHY. 



a double humeral tract, such as has already been described in Picus, and which occurs here still 

 more distinctly. Moreover, the large inferior humeral tract is much stronger and broader than 

 in the true Macaws. In P. pertinax I found twenty-one remiges, of which the first was very 

 little shorter than the second and third, and these are of the same length as the fourth, which is 

 distinguished by a remarkable and almost abrupt narrowing and acumiimtion of the extremity of 

 its vane, whilst the fifth is perceptibly shorter even than the first. I found precisely the same 

 structure in P. auricapillus, HAHN (Sittace jendaya WAGL.) and P. solstitialis, two species 

 which closely resemble P. pertinax in their pterylosis, and, like it, are provided with a small, 

 deeply bilobed oil-gland, beset at the tip with six umbellate down-feathers. On the other 

 hand, this is wanting in P. viridissimus, KUHL (P. rufirostris, ILLIG., LIGHT. ; Sitt. tirica, 

 WAGL.), which certainly also belongs to this group, and in which I could not detect the above- 

 mentioned acurnination of the fourth primary. These species are entirely destitute of powder- 

 down feathers. 



Domicella WAGL. 1 The pterylosis of the two species of this genus examined by me, 

 namely, P. domicella AUCTT. (D. atricapilla WAGL.), and P. garrulus, agrees almost exactly with 

 that of P. pertinax ; but the inferior tract was more sparsely feathered, and its branch by no 

 means so distinctly differentiated from the main stem by a stronger formation of the feathers. 

 The inferior space, separating its two halves, terminated at the bottom of the throat, so that the 

 plumage of the lower surface of the neck was uninterrupted. On the other hand, the lumbar 

 tract consisted of three rows of feathers, and coalesced anteriorly with the crural tract (which, as 

 in the Raptorial Birds, formed breeches), and posteriorly with the dorsal tract. Both the humeral 

 tracts were present, but the smaller one only indicated as an angle, the larger one consisting of 

 two rows of feathers. Twenty-one remiges ; the first ones rather acute ; the first as long as the 

 third, the second the longest. Oil-gland present in both, rather broad, its halves thick, closely 

 approximated, the tip cylindrical, rather long. No powder-down feathers. 



3. Triclioylossus WAGL. Of this group I have examined only T. h(ematodes, and have 

 ascertained that it is distinguished by comparatively narrow tracts. The inferior tract has a 

 very distinct outer branch upon the breast, between which and the weaker main tract there are, 

 however, a few contour-feathers. The hinder part of the dorsal tract was very briefly forked, so 

 that the simple stem of the fork is equal in length to the two branches. I found twenty-one 

 remiges and a distinct oil-gland, but no powder-down feathers. 



4. Psittacus WAGL. From my investigation of P. erithacus, dominicensis, ochrocephalus, 

 leucocephalus and dufresnianus, the species of this genus appear to belong to two pterylographic 

 groups, for P. erithacus exhibited no trace of an outer branch on the inferior tract, and presented 

 precisely the same characters as P. domicella and P. pertinax ; whilst in P. dominicensis and the 

 other American species, the biserial strongly and densely feathered outer branch is distinctly 

 separated from the sparsely feathered main tract. The dorsal tract is of the usual formation as 

 far as the fork, but in P. dominicensis the posterior or covered portion forms a general, sparse 

 plumage coalescing with the femoral and crural tracts, in which a furcate division can only be 

 recognised in front, but no densely feathered fork-stem is to be observed posteriorly ; whilst in 



1 Wagler says in the character of this genus, " lingua simplex glabra ;" but I find in both species 

 that the tongue is as strongly spinose as in Trichoglossus hfematodes, with which, therefore, these 

 species should be united. [This fact has been subsequently noted by Dr. Weiuland, ' Journ. f. Oru.,' 

 No. xii, p. Ixix, and Mr. Wallace, 'Ann. N. H.,' 1859, Feb., p. 147. P.L.S.] 



