FOSSIL FEATHERS AND UNDESCRIBED FOSSIL BIRDS 647 
in sight to make certain of this.‘ It is the right side of the body 
of the bone that is exposed in the specimen; and, as its posterior 
border had four notches—that is, two on either side of the carina— 
the sternum of that bird differed in this particular from all typical 
existing passerines as they now occur in North America, at least 
north of Costa Rica.’ 
Many years ago, in speaking of the Pteroptochidae, Sclater 
pointed out that this assemblage ‘“‘must remain, therefore, as an 
independent family of themselves, to be placed, according to my 
views, at the end of the Tracheophonine section of the Passeres, 
and at once distinguishable from all other Passeres by the posterior 
margin of the sternum being doubly emarginated as in the Pici 
and many Coccyges.’’ 
That this bird was a passerine species with a four-notched 
sternum, and not a cuckoo or a woodpecker, is at once evident 
when we come to examine the remainder of that bone, and find 
that it possesses a large manubrium which is bifurcated anteriorly, 
thus producing two diverging apophyses, as is the case in the ster- 
num of any true passerine form. This sternum has a mesial length 
‘See note above (on original label) in regard to sternum of the Preroptochidae. 
I have not examined the sternum in Scytalopus argentifrons of Costa Rica 
(see Ridgway, Proc. U.S. Nat. Mus., XIV [1891], 475; Sharpe, Hand-List, 111, No. 13, 
p. 5). Possibly it may have a four-notched sternum; but there is no material at my 
hand either to prove or disprove it. 
3P. H. Sclater, “On the Neotropical Species of the Family Pteroptochidae,”’ 
The Ibis, 3d Ser., No. XV, July, 1874, Art. XXIII, p. 191 (Plate VIII), of Rhino- 
crypta fusca. “The only other known Passerine form in which two emarginations are 
present on each side of the posterior margin of the sternum is the Australian genus 
Atrichia. Whether this form certainly belongs to the Pleroptochidae cannot be posi- 
tively ascertained until the structure of its larynx is known; but I have little doubt 
that such is the case. There is a sternum of Alrichia rufescens in the Cambridge 
Museum.” 
To this I may add that on this date (July 1, 1913) there is not an alcoholic speci- 
men, nor a vestige of a skeleton of any of the species of the Pteroptochidae in the col- 
lections of the U.S. National Museum for anatomical examination. 
A. H. Garrod presented a sternum of Hylactes megapodius to the Museum of the 
Royal College of Surgeons of England; but I have never seen the specimen (S.S. 2660) 
(Cat. Mus. R. Coll. of Surg. of Eng., 1891, p. 123). 
4R. W. Shufeldt, Fig. 58 in Key to North American Birds (Vol. I, E. Coues, 5th 
ed., p. 151). This figure gives a ventral view of the “‘typical passerine sternum of 
the robin (Planesticus migratorius),”’ and in it the bifurcations of the manubrium 
of the bone are well shown. 
