ANSERES 



461 



patagial fan, a state of affairs which is exactly paralleled in 

 Mchmophorus (see p. 387) . In ducks there is a peculiarity in 

 the biceps to which attention appears to have been first 

 called by Fuebeingbe. There is a tendinous sheath 

 partly covering the patagial side of the muscle and derived 



Pig. 218. — Windpipe of 

 Sarcidiorms melanoia S 

 (after Gabbod). 



Fig. 219. — Same op 

 S. melanoia 2 

 (aftee Gabkod). 



Fig. 220.— Same of 

 Bhodonessa ca/ryo- 

 phyllacea 9 (apteb 

 Gabbod). 



from the pectoraHs primus. A similar structure occurs in 

 Colymbi and storks, and in Casuarius its homologue is more 

 independent of the biceps. The latter at any rate, if not 

 the former, seems to me to correspond to a pecuhar muscle 

 found in the tinamous (cf. p. 489). 



The expansor secundariorum shows some variations. In 

 Biziura lobata it is entirely absent. In Aix sponsa the 

 tendons thin off and are lost on the interthoracic septa. In 

 others as, for instance, Bernicla canadensis, the expanded 

 tendons end upon the oesophagus ; on the way thither they 



