530 MR. W. BATESON OX AN ABNORMAL FOOT OF A CALF. [June 20, 



I consider that for the present the following species only can stand 

 as distinct : — 



1. Cyanorhamphus ulletanus (Gm.). Society Islands. 



2. G. erythronotus (Ivuhl). Society Islands. 



3. C. unicolor (Vig.). Antipodes Island. 



4. O. novc, zealandice (Sparrui.). JS'ew Zealand, Chathams, 



Auckland I. 



5. C. cooki (G-. E. Gray). Norfolk Island. 



6. C. suhjlavescens, Salvad. Lord Howe Island. 



7. C erythrotis (Wagl.). Macquarie Is. and Antipodes I. 



8. 0. saisseti (Yerr. & Des Murs). New Caledonia. 



9. C. cyanurus, Salvad. Kerniadec Islands. 



10. G. auriceps (Kuhl). New Zealand. 



11. G. malherbci, Souance. South Island, New Zealand. 



12. G. forbesi, Eothsch. Chatham Islands. 



Mr. W. Bateson exhibited an abnormal foot of a calf, which 

 had been forwarded to him for examination by the kindness of 

 Mr. W. L. Sclater. 



The specimen was a right fore foot, bearing three digits disposed 

 almost symmetrically with regard to the axis of the limb. Of the 

 carpus only the distal row remained, consisting of the usu:il two 

 elements, a trapezoido-magnum and an unciform. External to the 

 unciform the small rudiment, considered as representing the fifth 

 digit, was of the usual size and proportions. The upper end of the 

 metacarpal bone presented no peculiarity. Peripherally, however, 

 instead of the usual two articular surfaces the metacarpal in this 

 limb had three articular surfaces, all standing in the same plane as 

 those of a normal limb. Each articular surface is well formed and 

 has a large trochlear ridge. The central articular surface differs a 

 little from the other two, being slightly crowded against the 

 external one. In it also the trochlear ridge does not exactly divide 

 the articular surface, but is rather nearer to the external side. 

 With each of the three surfaces articulates a digit containing three 

 phalanges of full length. Over each articulation is a pair of normal 

 sesamoids, three pairs in all, instead of two pairs. 



Each digit bears a hoof. The hoof of the middle digit is convex 

 on both sides, but each of the lateral hoofs is convex on its outer 

 side and concave on the side turned towards the hoof of the middle 

 digit. The small accessory hoofs, the ergots of French writers, are 

 normal and stand in their usual positions with regard to the limb, 

 one being above and slightly external to the metacarpo-phalangeal 

 articulation of each of the outer digits. The limb is almost 

 exactly symmetrical about a line taken through the centre of the 

 middle toe. Each of the toes had well-formed flexor and extensor 

 tendons. 



In the normal metacarpus of the Ox there is in the peripheral 

 third a median groove of some depth, indicating the line of 

 demarcation between the metacarpals III. and IV. It is in this 



