LEGS AND FEET OF ICHTHYORNIS 173 



The tibia in Apatomis is somewhat larger and stronger than in 

 Ichthyomis. The proximal end of the bone is unknown, and the upper 

 part of the shaft is much crashed and mutilated in the specimen preserved. 

 Distally, it is straighter than in IcMhyornis, and expands to about the same 

 degree. As in that genus, there is no osseous supratendinal bridge, nor is 

 there any apparent roughening for the attachment of the end of the fibula. 



The measurements given below indicate the size of the tibia in several 

 specimens of the Oclontotormoe : 



Measurements of Tibia. (Ichthyomis dispar, No. 1450.) 



Greatest diameter of proximal end, 5.0 mm 



Greatest antero-posterior diameter, 4.5 



Transverse diameter of shaft, including fibular ridge, 4.0 



Transverse diameter of shaft, below fibular ridge, 2.8 



Antero-posterior diameter of shaft, below fibular ridge, 2.0 



Greatest diameter of distal end, 5.0 



Antero-posterior diameters of distal end, 4.0-2.0-4.0 



Measurements of Tibia. (Ichthyomis dispar, No. 1723.) 



Length of tibia, 57. ml " 



Transverse diameter of shaft, 3. 



Transverse diameter of distal end, 5.3 



Antero-posterior diameter of inner condyle, 4.7 



Antero-posterior diameter of outer condyle, 4.1 



Measurements of Tibia. (Ichthyomis victor, No. 1732.) 



Length of tibia, 57. mm 



Diameter of shaft, 3. 



Transverse diameter of distal end, 6.1 



Antero-posterior diameter of outer condyle, . _ 5. 



Measurements of Tibia. (Apatornis celer, No. 1734.) 



Transverse diameter of distal articulation, 6.5 mra 



Least antero-posterior diameter of distal articulation, 3. 



Antero-posterior diameter of outer condyle, 5.5 



Antero-posterior diameter of inner condyle, 6. 



Transverse diameter of shaft, 4. 



