NO. 3 



COMPARATIVE HISTOLOGY OF FEMUR- 



1 FOOTE 



97 



LEFT FEMUR OF TRICHOSURUS VULPECULA. PHALANGER. NO. 22804, 



AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 184. Syn. Tab. V 



Antero-posterior diameter of bone, 7 mm. ; lateral, 7.5 mm. 

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

 The medullary canal is full. Medullary index, 61%. 



Structure. — The section is composed of lamellae with long lacuna? and 

 straight canaliculi, interrupted by a few Haversian systems of the (la) and 

 (lb) differentiations and crossed radially by vascular canals. 



The bone shows very little differentiation of structure. The bone is uni- 

 form. 



Type I-III, la, lb. 



LEFT FEMUR OF PHASCOLOMYS URSINUS. WOMBAT. AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 185. Syn. Tab. V 



Antero-posterior diameter of bone, 11.5 mm. ; lateral, 13 mm. 

 Antero-posterior diameter of medullary canal, 4 mm. ; lateral, 6 mm. 

 The medullary canal is full. Medullary index, 11%. 



Structure. — The section is composed of several concentric rings of lamella? 

 with long lacunae and straight canaliculi surrounding the medullary canal. 



The rings of lamella? are separated by small, crude Haversian systems of 

 the (la) and (lb) differentiations and crossed radially by many canals. The 

 posterior ridge is double. The two ridges are composed of very crude Ha- 

 versian systems and inter-Haversian lamella?. Between them and forming the 

 posterior wall the structure is the same as elsewhere. 



The lacuna? are long and oval and the canaliculi are long, straight, or bushy. 

 The bone shows but little differentiation of structure. 



Type I-III, la, lb. 



RIGHT FEMUR OF LASIOPYGA KOLBI. AFRICAN MONKEY. NO. 27719, 

 AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 186. Syn. Tab. V 



Antero-posterior diameter of bone, 8.5 mm. ; lateral, 10 mm. 

 Antero-posterior diameter of medullary canal, 6 mm.; lateral, 7 mm. 

 The medullary canal is full. Medullary index, 98%. 



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

 and bushy canaliculi, interrupted by small crude Haversian systems of the (la) 

 and (lb) differentiation enclosing the medullary canal. A few fairly well de- 



