394 



M ERISTIC VARIATION. 



[PART I. 



Mu-eum. The specimen is No. 76,221 in that collection, marked "Greenland, 

 S.j.t. ls77; Loc. Kumlicn.' The accompanying figures were kindly made for me 



II 



C. 



FIG. 122. Larus lettcopterus, No. 605. 



A. Right foot seen from in front. 



B. The same from the internal side. 



C. Left foot from in front. 



From a drawing of specimen in U. S. Nat. Mus., kindly made for me by Prof. 

 RIDGWAY'S direction. 



under Professor Ridgway's supervision and sufficiently shew its structure (Fig. 122). 

 [It will be seen that tin 1 hallux in A, the right foot, appears on the outside; this I 

 conceive is due to partial rotation to shew the abnormal toes.] 



Besides these there are a few amorphous cases of extensive repetition of digits in 

 birds. 



These facts shew how fruitless a work it is to try to find a 

 statement \\liifli -hall includ'- all tin- cases. There is an 

 almost unbroken series of conditions starting from either duplicity 

 of the hallux, or from the presence of an internal rudimentary 



