ON THE BURSA FABRICII IN BIRDS. 



4. NOTE ON MR. WALLACE'S DISTRIBUTION Nature,' xr. 



OF PASSERINE BIRDS.* P- 58 (1876). 



IN Mr. Wallace's recently published work on Geographical Distribution, 

 in more than one place the results arrived at from an inspection of his 

 elaborate tables of genera and families do not agree with the numbers he 

 uses considering the general bearing of the facts adduced. Thus, in his 

 " General Remarks on the Distribution of the Passeres," vol. ii. pp. 299- 

 302, he says (1. c. p. 300) : " The families that are confined to single 

 regions are not very numerous, except in the case of the Neotropical 

 region, which has Jiue, the Australian has only three, the Oriental one, 

 Ethiopian one, and the other regions have no peculiar families." 



Adopting his tables of the families of the Passeres, I find the numbers 

 should be really as follows : 



Neotropical 7 Fams. Nos. 39a, 40, 41, 42, 44, 45, 46. 



Australian 5 21, 22, 25, 49, 50. 



Oriental 3 11, 12, 43. 



The Nearctic region should also be mentioned as possessing one 

 peculiar family, i. e. ChamaeidaB. The statement that none of the turdoid 

 Passerine families are exclusively American must also be modified to 

 meet this fact. There are three families (i. e. Paictidae, Pittidae, Eury- 

 laemidoo) instead of two of the Formicaroid Passeres in the Old World, 

 of which the Pittidae can hardly be said to have only a " very restricted 

 distribution." 



The Australian genus Struthidea, of doubtful position, seems omitted 

 altogether. 



5. ON THE BURSA FABRICII IN BIRDS.f P.Z.S. 1877, 



p. 304. 



PROF. GAEEOD, in his paper on Plotus mihinga (P. Z. S. 1876, p. 344) 

 says : " In the urino-genital system of Plotus anliinga, in both sexes, the 

 ducts open in the normal manner into the cloaca, just above its lower orifice. 

 This orifice, however, is not on the surface, but is into a cavity behind 

 the cloaca, which opens externally .quite close to the place where the two 

 communicate. Except for the nearly marginal orifice, the second cavity 

 is a csDcal sac, oval in shape, and about 1| inch high, covered at its blind 



* ' Nature,' xv. p. 58 (1876). 



t Proc. Zool. Soc. 1877, pp. 304-318. Read April 17, 1877 



B2 



