84 SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE VOL. 35 



BIGHT FEMUR OF MEGADERMA SPASMA. NO. 114272, U. S. NAT. MUS. 



Pl. 8, Fig. 145. Syx. Tab. IV 



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



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



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



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

 and bushy canaliculi. The lamellae are divided into wide external and narrow 

 internal rings which partly surround tlie medullary canal. The internal ring is 

 limited to the lateral walls. The bone shows a partial twofold division. 



Type I. 



BIGHT FEMUB OF PTEBONOTUS. NO. 113570, U. S. NAT. MUS. 



PL. 8, Fig. 140. Syx. Tab. IV 



Antero-posterior diameter of bone, 1 nmi. ; 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 FEMUB OF BALANTIOPTEEYX PLICATA. NO. 142606, U. S. NAT. MUS. 



Pl. 8. Fig. 147. Syx. Tab. IV 



Antero-posterior diameter of bone, 0.5 mm.; lateral, 0.5 nmi. 



Antero-posterior diameter of medullary canal, 0.3 mm. ; lateral, 0.3 mm. 



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



Structure. — The section is composed of a few concentric lamellae with round 

 and oval lacunae and bushy canaliculi surrounding the medullary canal. The 

 bone is uniform. 



Type I. 



BIGHT FEiM V& OF SACCOPTERYX. NO. 123800, U. S. NAT. MUS. 



Pl. S. Fig. lis. Syx. Tab. IV 



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

 Antero-posterior diameter of medullary canal, 0.4 mm.; lateral, 0.3 mm. 

 The medullary canal is full. Medullary index, 18%. 

 The bone is flat on I lie pnstcr'uir side. 



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

 and bushy canaliculi surrouudiuii the medullary canal. The bone is uniform. 

 Type I. 



