State of the Systema Avium. 401 
Meropide, Coraciide, Momotide, and Todidz. The two last- 
named groups are united by Garrod into one family*. They 
all four have twelve tail-feathers, a naked oil-gland, and 
ceca. But to these must be added, as aberrant appendages 
(which sadly mar the uniformity of the group), the Lepto- 
somide and Podargide and, as it would appear from Prof. 
Garrod’s researches, the Coliidee. Leptosoma, as stated above, 
is clearly more allied to the Rollers than to any other form. 
Podargus cannot be left with the Caprimulgidee, looking to 
the conformation of its palatal bones+, and comes in best 
here, whereas Nyctibius belongs truly to the Caprimulgidet. 
After Garrod’s exhaustive disquisition on Steatornis§, we can 
no longer complain that its structure is unknown; but it 
becomes still more difficult, owing to its numerous peculi- 
arities, to arrange this most extraordinary bird in a satisfac- 
tory place in the series. It must certainly be either put in here 
or placed as a separate order next to the Striges. Perhaps 
the former plan is for the present the most convenient. 
With these additions the Anisodactyle, as we have called 
them in our ‘Nomenclator,’ will consist of the following 
twelve families :— 
1. Coliidee. 7. Momotide. 
2. Alcedinide. 8. Todide. 
3. Bucerotide. 9. Coraciide. 
4, Upupidee. 10. Leptosomidee. 
5. Irrisoridee. 11, Podargide. 
6. Meropide. 12. Steatornithide. 
The Heterodactyle, which follow next in the ‘ Nomenclator,’ 
consist of the single family Trogonide, the only form of the 
whole class of birds in which the fourth or outer digit is 
reversed instead of the second. ‘The pterylosis of Trogon 
is also quite different from that of the other Zygodactyle, 
being purely Passerime, except as regards its long aftershaft ||. 
The true Zygodactyle in the ‘Nomenclator’ consist of 
four families besides the Cuckoos, namely the Galbulide, 
* See P.Z. S. 1870, p. 101. 
+ Husley, P.Z. 9. 1867, p. 445. 
t+ Huxley, /. c. p. 454. § P.Z. 8S. 1873, p. 526. 
|| Nitzsch, Pterylogr. p. 93. 
SER. IV.—VOL. IV. 25 
