NO. O COMI'AEAIIVE HISTOLOGV OF FEMUR FOOTE 81 



RIGHT FEMT-R OF DASYPTERUS INTEEMEDIUS. NO. 22408, T'. S. NAT. MUS. 



Pl. S. Fig. 133. Syx. Tai:. IV 



Antero-posterior diameter of bone, 1 mm.; lateral, 0.!i iiiiii. 



Antero-posterior diameter of medullary t-anal, 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 external 

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

 and straight canaliculi, and the internal, of lamell* with long lacunae and straight 

 canaliculi. The bone lias the twofold division. 



TyiJe I. 



LEFT FEMUR OF MOLOSSUS MA.JOR. XO. 101893, U. S. XAT. MUS. 



Pl. 8, Fig. 134. Stx. 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 lamellfe with oval lacunaj 

 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 AXTROZOUS P.\LLIDUS. XO. 63386, U. S. XAT. MUS. 



Pl. 8. Fig. 13.5. Syx. Tab. IV 



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



Antero-posterior diameter of medullaiy 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 lacuna^ with bushy canaliculi surrounding the medullary 

 canal. The bone is uniform. 



Type I. 



LEFT FEMUR OF EtTMOPS CALIFORXICUS. XO. 61387, U. S. X.\T. MUS. 



Pl. 8. Fig. 136. Syx. 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 nmi. 



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



Structure. — The section is composed of concentric lamella? with oval lacuu* 

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

 Twofold division. 



Type I. 



