NO. 3 



COMPARATIVE HISTOLOGY OF FEMUR 



; FOOTE 



93 



RIGHT FEMUR OF MAOROPUS. WALLABY. NO. 22810, AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 174. Syn. Tab. V 



Antero-posterior diameter of bone, 14 mm. ; lateral, 14 mm. 

 Antero-posterior diameter of medullary canal, 10 mm. ; lateral, 10.5 mm. 

 The medullary canal is full. Medullary index, 115%. 



Structure. — The section is composed of lamellae with oval long lacuna 1 

 and straight canaliculi, interrupted in the posterior wall by vascular canals and 

 crude Haversian systems, and elsewhere by frequent radiating canals and 

 Haversian systems of the (la) differentiation. It is indistinctly laminated. 



Type I-III, la. 



LEFT FEMUR OF SOLENODON PARADOXUS (YOUNG). AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 175. Syn. Tab. V 



Antero-posterior diameter of bone, 5 mm. ; lateral, 4.5 mm. 

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

 The medullary canal is full. Medullary index, 165%. 



Structure. — The section is composed of lamellae with round and oval lacuna 1 

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

 and (lb) differentiation and crossed by many oblique and radiating canals 

 which take their origin in the medullary canal. The bone shows a very incom- 

 plete differentiation. 



Type I-III, la, lb. 



RIGHT FEMUR OF SOLENODON PARADOXUS (ADULT). AMER. MUS. NAT. HIST. 



Pl. 9, Fig. 176. Syn. Tab. V 



Antero-posterior diameter of bone, 6.5 mm; lateral, 5 mm. 

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

 The medullary canal is full. Medullary index, 94%. 



Structure. — The section shows the three divisions. The external circum- 

 ferential lamellae form a distinct ring around the section. It is widest in the 

 inner wall. The lacunae are long and the canaliculi are bushy and straight. The 

 central ring is composed of lamellae with oval lacunae and bushy canaliculi, 

 interrupted by crude Haversian systems of the (la) and (lb) differentiations. 

 The section is nearly all lamellae. The internal circumferential lamellae form a 

 fragmentary ring around the medullary canal. Their lacunae are oval and 

 straight and the canaliculi are straight. 



Type I-III, la, lb. 



