On the Tarsus and Carpus of Birds. 157 



Ficr. 36. Tardus fuscescens. E. 21. 

 Showing four carpals. 



Fig. 37. Tardus fuscescens. 



A slightly more advanced stage, showing the third and fourth carpal 

 bones about uniting. The fourtli carpale sending out a process to third 

 metacarpal. The ulnare apparently uniting with ulna. 



Fig. 38. Turdus fuscescens. 



The same carpus under slight pressure. The ulnare separate again. 



Fig. 39. Quiscalus versicolor. E. 25. 



Showing the minute third carpale and the elongated ulnare. 



Fig. 40. Molothrus pecoris. E. 22. 



The third and fourth carpale united. 



Fig. 41. Sialia sialis. 



Third and fourth carpale about uniting, and fourth carpale sending out 

 peculiar process to third metacarpal. 



Fig. 42. 8ialia sialis. E. 31. 



A slightly more advanced stage, in which the distal carpals and base 

 of metacarpals are all united. 



Fig. 43. Cotyle riparia. E. 27. 



Anchylosis far advanced. Ulnare supposed to have united with ulna. 



Fig. 44. Dendroeca oestiva. E. 24. 



Ulnare supposed to have united with the ulna. The carpal marked i, 

 supposed to be intermedium. Third and fourth carpale united. 



Fig. 45. Hirundo lunifrons. E. 30. 

 The four carpals all separate. 



Fig. 46. Tijrannus Carolinensis. E. 23. 



Showing excessively long radiale. 



Fig. 47. Tijrannus Garolinensis. 



Another specimen under pressure, with a new carpal? supposed to be 

 centrale. 



Fig. 48. Tyrannus Garolinensis. 



Another specimen under pressui-e, in which the long ulnare readily 

 separates, leading to the supposition that the second carpale is here 

 present. 



The peculiar form of ulnare in Tyrannus, fig. 47, is seen also in Moloth- 

 rus and Sialia, flgs. 40, 42 and 43. 

 Apkil, 1872. 11 Ann. Lyc. Nat. Hist., Vol. x. 



