NO. 3 



COMPARATIVE HISTOLOGY OP FEMUR- 



; FOOTE 



99 



RIGHT FEMUR OF VIVERRA. CIVET. AMER. MUS. NAT. HIST. 



PL. 10. Fig. 190. Syn. Tab. V 



Antero-posterior diameter of bone, S mm.; lateral, 7 mm. 

 Antero-posterior diameter of medullary canal, 5 mm. ; lateral, 4 mm. 

 The medullary canal is full. Medullary index, 55%. 



Structure. — The section has three divisions. A wide ring of lamella?, dimly 

 separated into concentric parts and frequently interrupted by Haversian sys- 

 tems of the (la) differentiation, forms the greater part of the bone. The 

 lacuna? are oval and the canaliculi are bushy and straight. Underneath this 

 is a long crescent of Haversian systems of the (lb) differentiation surround- 

 ing the section with the exception of the inner wall. The systems are separated 

 by bone substance with round lacuna? and bushy canaliculi. 



A narrow ring of lamella? with long lacuna? and straight canaliculi sur- 

 rounds the medullary canal. 



Type I-III, la, lb. 



RIGHT FEMUR OF RATUFA MAXIMA. GIANT SQUIRREL. NO. 22839, 

 AMER. MUS. NAT. HIST. 



Pl. 10, Fig. 191. Syn. Tab. V 



Antero-posterior diameter of bone, 5.5 mm. ; lateral, 6.5 mm. 

 Antero-posterior diameter of medullary canal, 3.5 mm. ; lateral, 4.5 mm. 

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



Structure. — The section is surrounded by a wide ring of lamella? with long 

 lacuna? and straight canaliculi, interrupted by Haversian systems of the (la) 

 differentiation. In the posterior and outer wall is a narrow ring of small 

 Haversian systems of the (lb) differentiation. The internal circumferential 

 lamella? are not distinct. 



Type I-III, la, lb. 



FEMUR OF GALEOPITHECUS. FLYING LEMUR. NO. 49640, U. S. NAT. MUS. 



Pl. 10, Fig. 192. Syn. Tab. V 



Antero-posterior diameter of bone, 6.5 mm.; lateral, 5.5 mm. 

 Antero-posterior diameter of medullary canal, 4 mm.; lateral, 3.5 mm. 

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



Structure. — The section is composed of a wide ring of external circum- 

 ferential lamella? with long lacuna? and straight canaliculi, frequently inter- 

 rupted by small, crude Haversian systems of the (la) differentiation. The 



