356 MR. R. S. WRAY ON THE MORPHOLOGY [Apr. .5, 



it indicates the number of rows, and placing these symbols above or 



below a line, thus ^:jJ^ their dorsal or ventral position ; the mar- 



ginals are expressed by ju, the humerals by h, the axillars by .r, a 

 number after the h or'.r denoting the number of specialized feathers 



forming the "parapteron" and " hypopteron." When any two 



— '—, 

 rows are confluent it may be indicated thus, yx, where tbe axillars 

 and minores are indistinguishable as separate groups ; Al expresses 

 the quill-feathers of the pollex. 

 Formula for the Duck : — 



Mdll mQdb "jlllA (Pl9^^^y,A±IL AM. 

 a,/Ji7/i "i Pi 73 ^ 7(2-3) /* 



Typical Passerine formula : — 



MdlO mQ di "jAyiL C9 "'^'>'°^ A13. 

 "i 1^0 7A* «o Pi 7-2 A* 



Formula for Ostrich wing : — 



Md 16 7)1 8 d8 ^i& C20^^^jA1i^ AM. 

 «i "i 



These formulae might prove of value to ornithologists by enabling 

 them to briefly express the main characters of the wings of diiferent 

 groups of birds. The three given above at once express very great 

 differences in the wings of these birds : thus it is seen at once how, 

 in the Passerine, the upper minores, the axillars, and humerals are 

 absent ; and the whole of the lower coverts, except one row, in the 

 Ostrich. These are here introduced to show the possibility of using 

 a wing-formula expressing most of the characters. 



DESCKIPTION OF THE PLATES. 

 Plate XXIX. 



Drawing of a preparation of the right wing of the Wild Duct, seen from below, 

 sbow ing the relation of the quill-feathers to the bones. 



al. PlumaB pollicis (alula). C. Cubitals or secondary remiges. Md. Mel,a- 

 carpo-digitals or primary remiges. 3L Metacarpals. D. Digitals. Ad. 

 Addigital. Md 1 & 2. Middigitals 1 and 2. Pd 1. Predigital 1. Pd 2 or 7?. 

 Predigital 2 or remiole. H. Humerus. E. Kadius. Ul. Ulna. 8c. Scaphoid. 

 Cu. Cuneiform. Mc 1, 2, .3. Metacarpals 1, 2, 3. Ph 1, 2, 3. Phalanges 1, 

 2, 3. I., II., III. Digits I, 2, and 3, 



Plate XXX. 



a. Plan of the arrangement of the feathers on the dorsal surface of the extended 



left wing of Anas boschas. 

 h. Plan of the arrangement of the feathers on the ventral surface of the ex- 

 tended right wing of Avas hoschas. 

 C. Cubitals (grey). Md. Met^acarpo-digitals (grey), a. Tectrices majores 

 (pink). /3. Tectrices media; (green), y. Tectrices minores (brown). /<. Tec- 

 trices marginales (yellow). Al. Pluma3 pollicis (red). h. Humerals. x. 

 Axillars. x'. Axillary row of minores. 



