NO. 3 COMPARATIVE HISTOLOGY OF FEMUK FOOTE 99 



RIGHT FEMUR OF VIVEHKA. CIVET. AMEl!. MUS. NAT. HIST. 



Pl. 10, Fig. 190. Syk. Tab. V 1 



Antero-posterior diameter of bone, 8 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 lamelhe, dimly 

 separated into concentric parts and frequently interrupted by Haversian sys- 

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

 lacunae are oval and the eanaliculi are busliy and straight. Underneath this 

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

 ing the section with the excei^tion of the inner wall. The systems are separated 

 by bone substance with round lacunae, and bushy eanaliculi. 



A narrow ring of lamellas with long lacunae and straight eanaliculi sur- 

 rounds the medullary canal. 



Type I-III, la, lb. 



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



AMER. MUS. NAT. HIST. 



Pl. 10, Fig. 101. Syx. Tab. V 



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



Antero-posterior diameter of medullaiy 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 lamellje with long 

 lacunar and straight eanaliculi, interrupted by Haversian systems of tlie (la) 

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

 Haversian systems of tlie (II)) differentiation. The internal circumferential 

 lamelte are not distinct. 



Type I-III, la, lb. 



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



Pl. 10, Fig. 193. Sy>j. Tab. V 



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



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



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



Structure. — The section is composed of a wide ring of external cin/um 

 ferential lamelhiL' with long lacunae and straight eanaliculi, frequently inter- 

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



