NO. 3 COMPARATIVE HISTOLOGY OF FEMUR FOOTE 81 



RIGHT FEMUR OF DASYPTERUS INTERMEDIUS. NO. 22408, U. S. NAT. MUS. 



Pl. 8, Fig. 133. Syn. Tab. IV 



Antero-posterior diameter of bone, 1 mm. ; lateral, 0.9 mm. 

 Antero-posterior diameter of medullary canal, 0.5 mm. ; lateral, 0.4 mm. 

 The medullary canal is full. Medullary index, 29%. 



Structure. — The section is composed of lamella? divided into wide externa! 

 and narrow internal rings. The external consists of lamellae with oval lacuna; 

 and straight canaliculi, and the internal, of lamellae with long lacunae and straight 

 canaliculi. The bone has the twofold division. 



Type I. 



LEFT FEMUR OF MOLOSSUS MAJOR. NO. 101893, U. S. NAT. MUS. 



Pl. 8, Fig. 134. Syn. Tab. IV 



Antero-posterior diameter of bone, 0.6 mm. ; lateral, 0.6 mm. 

 Antero-posterior diameter of medullary canal, 0.4 mm. ; lateral, 0.4 mm. 

 The medullary canal is full. Medullary index, 80%. 



Structure. — The section is composed of concentric lamellae with oval lacuna? 

 and straight canaliculi. Two divisions appear, external and internal. The 

 external is wide and the internal is narrow. The concentric divisions surround 

 the medullary canal. The bone shows a twofold division. 



Type I. 



LEFT FEMUR OF ANTROZOUS PALLIDUS. NO. 63386, U. S. NAT. MUS. 



Pl. 8, Fig. 135. Syn. Tab. IV 



Antero-posterior diameter of bone, 1 mm. ; lateral, 1 mm. 



Antero-posterior diameter of medullary canal, 0.8 mm. ; lateral, 0.8 mm. 



The medullary canal is full. Medullary index, 178%. 



Structure. — The section is thin-walled and composed of concentric lamellae 

 with oval and round lacunae with bushy canaliculi surrounding the medullary 

 canal. The bone is uniform. 



Type I. 



LEFT FEMUR OF EUMOPS CALIFORNICUS. NO. 61387, U. S. NAT. MUS. 



Pl. 8, Fig. 136. Syn. Tab. IV 



Antero-posterior diameter of bone, 1.5 mm. ; lateral, 1.5 mm. 

 Antero-posterior diameter of medullary canal, 0.9 mm. ; lateral, 0.9 mm. 

 The medullary canal is full. Medullary index, 56%. 



Structure.— The section is composed of concentric lamellae with oval lacunae 

 and straight canaliculi, divided into wide external and narrow internal rings. 

 Twofold division. 



Type I. 



