ON THE ANATOMY OF PASSERINE BIRDS. 365 
beyond the second. This condition is just reversed in the two birds 
under consideration. In the Finches the arrangement described by 
Cuvier maintains, both anterior and posterior long muscles running 
_ to the third bronchial semiring. 
In Plate [25] LII. fig. 7 the sternum of Atrichia is figured with the 
rudimentary clavicles (f), which are nothing more than granules of 
bone. No other Passerine bird wants the furcula, so far as is yet 
known. The manubrium sterni is not largely expanded. : 
There is another feature in Passerine anatomy which has interested 
me considerably during my investigations. It is the rule among 
birds, almost without exception, that the main artery of the leg is that 
which must be supposed to be represented in Man by the comes nervi 
ischiaticit, it accompanying the sciatic nerve—the sciatic artery. 
The main nerve of the leg is the sciatic; the main vein the femoral. 
The only known exceptions to this rule are the cases of the genus 
> Dacelo among the Alcedinide, and Centropus among the Cuculide. 
In the former the femoral vein is replaced by the one which is inter- 
mediate in situation between its usual course and the sciatic artery; in 
the latter the sciatic artery is absent,* and is replaced by the femoral.t 
In a certain few Passerine birds the main artery of the leg is the 
femoral, and not the sciatic. These genera are all members of the 
Oligomyodi of Miiller; and the accompanying list contains the names 
of all the Oligomyodian species (taken from Messrs. Sclater and 
_ §$alvin’s “‘ Nomenclator Avium Neotropicalium ” {) which I have had 
the opportunity of examining, with the results arrived at, as far as 
this peculiarity is concerned. 
Passeres Oligomyodi. 
Z —~ ~ Page 517. 
With a femoral artery. With a sciatic artery. 
Chiroxiphia linearis, Mionectes oleagineus, 
Chiromacheris vitellina, Tyranniscus vilissimus, 
Heteropelma verepacis, Pitangus sulphuratus, 
Tityra personata, Myiodynastes luteiventris, 
Hadrostomus aglaie, Empidonaz minimus, 
Lipaugus sp., Myiarchus crinitus, 
Cotinga cincta, Tyrannus melancholicus, 
Chasmorhynchus nudicollis. Rupicola crocea, 
Pitta angolensis, 
Pitta cyanura. 
I must mention also that in a specimen of the minute Mitrephorus 
* [This is so only in Centropus phasianus, and does not occur in two other species 
of that genus dissected by Prof. Garrod.—Eb. ] 
+ “ Proceedings of the Zoological Society,” 1873, p. 629. (Suprd, p. 191.) 
t London, 1873. 
