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SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



VOL. 35 



Structure. — Tlie section is flattened antero-posteriorly and is surrounded 

 by external circumferential lamella 1 . The central ring is widest and is com- 

 posed of oval lacunae with very delicate bushy canaliculi. The posterior wall 

 has two ridges. In the outer ridge is a vascular canal. The bone shows the 

 threefold division. 



Type I. 



LEFT FEMUR OF LEPTONYCTERIS. NO. 105129, U. S. NAT. MUS. 



Pl. 8, Fig. 121. Syn. Tab. IV 



Antero-posterior diameter of bone, 1 mm. ; lateral, 0.8 mm. 

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

 The medullary canal is full. Medullary index, 33%. 



Structure.- — The section is composed of concentric lamellae divided into wide 

 external and narrow internal rings. The external is composed of lamellae with 

 oval lacunas and bushy canaliculi, and the internal, of lamellae with long, narrow 

 lacunae and straight canaliculi. The bone has the twofold division. 



Type I. 



KIGHT FEMUR OF RHINOPOMA. (PALESTINE.) NO. 122140, U. S. NAT. MUS. 



Pl. 8, Fig. 122. 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 concentric lamellae with oval lacunae 

 and straight canaliculi surrounding the medullary canal. The bone is uniform. 

 Type I. 



LEFT FEMUR OF EROPHYLLA BOMBIFRONS. NO. 86262, U. S. NAT. MUS. 



Pl. 8, Fig. 123. Syn. Tab. IV 



Antero-posterior diameter of bone, 1 mm.; lateral, 0.8 mm. 

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

 The medullary canal is full. Medullary index, 33%. 



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

 and straight canaliculi surrounding the medullary canal. The bone is uniform. 

 Type I. 



LEFT FEMUR OF PHYLLOSTOMA HASTATUM. NO. 102906, U. S. NAT. MUS. 



Pl. 8, Fig. 124. Syn. Tab. IV 



Antero-posterior diameter of bone, 2.5 mm. ; lateral, 1.5 mm. 

 Antero-posterior diameter of medullary canal, 1.5 mm. ; lateral, 1 mm. 

 The medullary canal is full. Medullary index, 64%. 



