470 Johnson, A Four-winged Wild Duck. [oct? 



records a "four-winged chick" but his specimen is of an entirely 

 different character, possessing not only four wings but also four legs, 

 and two tails. The spine is bifid, beginning at the base of the neck, 

 and each spinal column has a corresponding pair of wings, a pair of 

 legs and a tail. Diard ('97) reports a four-footed duck six months 

 old. In this case there is a supernumerary pair of feet separate 

 and distinct as far as the ankle joint, where each has its own artic- 

 ulation with a bifid enlargement at the end of a shaft of bone which 

 apparently corresponds to fused tibio-tarsal elements of the two 

 appendages. There is no distinct femoral segment differentiated, 

 the feet being suspended from the previously mentioned shaft which 

 articulates with the pelvis on the left dorsal side, at the junction 

 of the synsacrum and caudal vertebrae. The feet themselves are 

 abnormal. The left is larger and possesses three toes fully webbed; 

 the smaller right foot has only two w r ell formed webbed toes and 

 an inner rudimentary digit. The fourth, posterior toe is lacking 

 in each. The feet are furthermore somewhat deformed and 

 atrophied and incapable of movement. 



Tornier ('01) describes among other abnormalities three hens 

 and two ducks, each with a pair of supernumerary legs appended 

 to an abnormal pelvis. In addition to the accessory limbs, each 

 of these specimens had two supernumerary cseca and the rectal 

 segment of the gut w'as forked, presenting two cloacal chambers 

 and anal openings. 



The subject of the present paper is an adult female Green-winged 

 Teal {Nettion carolinense) . In a letter describing the circumstances 

 in which the specimen was obtained, Mr. Stadon says : 



" It may be of interest to know that the bird had no difficulty in 

 flying but was peculiar from the fact that it flew out from some thick 

 grass bordering a small creek back in the w r oods, whereas this species 

 of duck, in my experience, more often stays along the protected 

 shore of a lake when resting. Furthermore, I had not seen another 

 Green-wing in that locality for at least tw T o weeks before this one 

 was killed. Pretty sure the rest of the species had migrated." 



External features. The left w T ing of the normal or primary pair 

 had been shot off at the elbow, otherwise the two sides are essen- 

 tially alike in external appearance. When the primary wings are 

 raised the supernumerary wings appear as a miniature set springing 



