1889. | Recent Literature. 26 7h 
which we most heartily do, is to make but faint recognition of the heavy 
obligations ornithologists must feel they are under to the author of the 
volume under notice. 
Of the thirteen families of so-called Mesomyodian Passeres only nine, 
forming the section Oligomyodz, are treated in the present volume; the 
remaining four (Tracheophone), all New World forms, will form the 
subject of a succeeding volume, by the same author, already nearly ready 
for publication. Of the families treated 655 species are recognized, 
represented in the British Museum Collection by 7360 specimens, only 
38 of the species recognized as valid being unrepresented in the collection, 
which includes 161 ‘‘actual ‘types’ of species” treated, and much other 
authentic material. The Tyrannidz number 409 species; the Oxyrham- 
phide, 5; the Pipride.79; the Cotingide, 110; the Phytotomide, 4; the 
Philepittide, 2; the Pittide, 50; the Xenicide, 3; the Eurylemidea, 11. 
The Tyrannide thus outnumber, nearly two to one, the species of all 
the other eight families collectively. As is well known to our readers, 
they are exclusively American, and mainly limited to the American 
tropics, although a few genera are widely dispersed over North America. 
“Their generally uniform plumage and similar external structure renders 
the discrimination of the species of the Tyrannide and their grouping 
into genera extremely difficult, and in many cases unsatisfactory.” Add 
. to this the considerable range of individual and seasonal variation occur- 
ring in many of the genera, and the difficulties in the way of the system- 
atist are in some cases well nigh disheartening. While many species 
‘‘no doubt remain to be discovered, as the more remote portions of South 
America come to be investigated,” it is equally certain that as more mate- 
rial is accumulated many hitherto currently recognized species will have 
to be reduced tosynonyms. As might be expected in large genera of 
closely allied species, brief descriptions, such as are given in the present 
work, fai: to discriminate, and the characters given in the ‘keys’ fail to 
throw much further light. This, in many cases, is the fault of the ‘species,’ 
but not infrequently the fault of haste in the preparation of the work. 
Commonly, however, a line or two is added to the description stating the 
supposed differences separating one closely allied species from another. 
In many instances the author is laudably conservative in respect to 
admitting species that have slight claims to admission, while in other 
similar cases judgment is apparently waived in favor of current tradition. 
In other cases species have been merged which are unquestionably 
distinct. 
Perhaps the most unsatisfactory feature of the work is the omission to 
give more than a brief description of an average adult bird, in cases 
where there is much seasonal variation in plumage, and often very great 
variation between adult and young. A case in point is Cofurus colonus, 
under which C. fuxebrzs Cab. & Hein. is placed as a synonym, without a 
word of comment, or any indication that the young bird is in any way 
different from the adult. The adult C. colonus is a black bird, with a 
white rump and a grayish white head, and the middle pair of tail-feathers 
