1915.| : Miller, Notes on Ptilosis. 139 
have not been examined: Gymnobucco, Smilorhis, Stactolema and V iridi- 
bucco.} 
It is often stated that in the Motmots the oil-gland is nude, but both 
Gadow and Beddard record feathered as well as unfeathered oil-glands in 
this family. Gadow mentions no genera, and Beddard merely states that 
“in Momotus the oil-gland is quite nude; in H ylomanes and Eumomota the 
apex is furnished with a few small plumes.’’ On examination of all seven 
genera I find a small but well-marked tuft in Hylomanes, Aspatha; Eumo- 
mota and Electron. In the remaining three genera the gland is usually 
perfectly bare, but close examination with a lens frequently reveals a very 
minute vestige of the tuft. This has been observed in Momotus swainsoni, 
Baryphthengus and Urospatha, and presumably occurs in other species of 
Momotus.? | : 
Aftershaft.— It has long been supposed that in the Osprey (Pandion) the 
feathers are without an aftershaft, and time and again has this alleged 
1 The commonly accepted classification of the tooth-billed forms above mentioned ap- 
pears to represent the natural inter-relationships of the genera very imperfectly. Erythro- 
bucco is so strikingly similar to Pogonorhynchus in coloration and general form, scarcely 
differing except in the absence of corrugations on the lower mandible, that the desirability 
of separating it generically is surely open to question. Whether or not it be kept apart, 
however, it seems necessary to restrict Lybius (type L. tridactylus) to the smaller, black-billed 
species, distinguishing the several white-billed species as Melanobucco (type M. bidentatus). 
Despite their simple bill and few bristles the latter are evidently more nearly related to 
Pogonorhynchus and Erythrobucco than to Lybius. They differ from the latter in larger size, 
longer tail, larger, distinctly double-notched, white bill, and in coloration, in all of which 
they agree with or closely approach the former genera. The coloration of the type of Melano- 
bucco is remarkably similar to that of Erythrobucco and Pogonorhynchus with which it shares 
the tuft of narrow, elongated white dorsal feathers, and the thick almost truncate bunch of 
white feathers:on each side of the body. 
That these peculiarities of color and plumage were evolved independently is highly 
improbable, and it would be fallacious to consider Melanobucco as more nearly related to 
Lybius merely because of general agreement in the unspecialized bill and its bristles. Study 
of the geographical distribution confirms the naturalness of the arrangement suggested. 
Since the above was written the second volume of Reichenow’s ‘‘ Die Végel’’ has come to 
hand. This author combines Erythrobucco with Pogonorhynchus as above suggested. 
2'The four genera with tufted oil-glands have their center of distribution in Central 
America, three of them (all monotypic) and one species of Electron being confined to this 
region; the single remaining species of Electron ranges from Nicaragua to Ecuador. They 
are further characterized by the broad, depressed bill with very finely serrate tomia, and their 
average size is much less than that of the remaining species. 
The latter possess a much narrower and deeper, coarsely serrate bill. While well repre- 
sented in Central America one of the three genera (the monotypic Baryphthengus) is confined 
to Brazil. These two groups may well be regarded as subfamilies, the Hylomanine and the 
Momotine. 
The Hylomanine show a marked approach to the Todidez. This is evident in the de- 
pression of the bill and its fine serration, and in the tufted oil-gland. Furthermore, in Aspatha 
and Hylomanes the tomium is nearly straight and the middle rectrices of normal form, while 
in Hylomanes, which is by far the smallest member of the family, there is no tuft of black 
feathers on the chest. The geographical distribution is also significant. 
In each of the subfamilies both normal and spatulate central rectrices occur. The 
intraspecific variation in this respect in Urospatha martii and Electron platyrhynchus, how- 
ever, greatly reduces the taxonomic value of this character in the Motmots. 
