196 MR. H. E. STRICKLAND ON SOME BONES OF BIRDS ALLIED TO THE DODO. 



brought to light. These are, first, the considerably less development of the inner or 

 longest calcaneal process in Pezophaps as compared with Didus. Thus, while the 

 antero- posterior diameter of the proximal extremity in the tarso-metatarsus of Didus 

 amounts to 1 inch 4 lines, the same measurement in Pezophaps minor reaches only 

 1 inch 1 line. Again, at the lower extremity we find that the three trochlese are placed 

 more nearly in the same vertical plane in Didus than they are in Pezophaps, in which 

 latter bird the two lateral trochleae are placed more obliquely and more posteriorly in 

 reference to the middle one than they are in Didus. This arrangement seems to imply 

 a greater divergence in the lateral toes of Pezophaps than in those of Didus, which 

 would probably enable the former bird to run with a speed never attained by the latter. 

 The peculiar position of the calcaneal canal on the outer side of the posterior ridge, 

 which distinguishes the Pigeons, and the allied group of PteroclidtB, from all other birds, 

 and which forms one of the strongest proofs of the Columbine affinities of the Dodo, is 

 well seen in the bone No. 18. It fully justifies our former conclusions not only as to 

 the proximity of Pezophaps and Didus, but as to the position of both these birds, show- 

 ing that they are a peculiar and exceptional, yet in all essential points a genuine sub- 

 family of that great and isolated family the Columbidce. 



The views of ornithic structure, which the examination and comparison of these 

 scattered relics have thus gradually developed, render it more than ever desirable to 

 search for other portions of the skeleton of the different members of the group DidiruB 

 which once inhabited the Mascarene Islands. Of the two species of Pezophaps from 

 Rodriguez, many important parts of the skeleton, and especially the cranium, have yet 

 to be discovered. Of the Didus of Mauritius we still want the femur, the tibia, and all 

 the bones of the body and anterior extremities, while of the so-called "Solitaire" of 

 Bourbon not even a fragment has yet been brought to Europe. After the success, 

 however, which has attended similar researches in New Zealand, we cannot doubt that 

 an active naturalist, by excavating the alluvia of these different islands, might restore 

 the entire skeletons of these extraordinary birds. 



