94 SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE VOL. 35 



FEMUR OF LEMUK MONGOZ. NO. 86849, U. S. NAT. MUS. 



Pl. 0. Fig. 177. Stn. T.\b. V 



Antero-iiosterior diameter of bone, 9 mm. ; lateral, 7 mm. 



Antero-posterior diameter of medullar}' canal, 7 mm. ; lateral, 4.5 mm. 



The medullary canal is full. Medullary index, 100%. 



Structure. — The section is composed of lamella; Avitli long lacunae and 

 straight canaliculi, divided into wide external and narrow internal rings. The 

 lamellae of the external ring are interrupted by small and rather crude Ha- 

 versian systems of the (lb) differentiation and by vascular canals which occupy 

 a concentric position in the wall of the bone. The internal ring of lamelte with 

 long lacunae and straight canaliculi surrounds the medullary canal. The bone 

 has the twofold division. 



Type I-III, lb. 



LEFT FEMUR OF COLOBUS ABYSSINICUS CAUDATUS. NO. 27711, AMER. MUS. NAT. HIST. 



PL. 9, Fig. 178. Syn. Tab. V 



Antero-posterior diameter of bone, 12.5 mm. ; lateral, 13 mm. 



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



The medullary canal is full. Medullary index, 43%. 



Structure. — The section is composed of a very wide band of external cir- 

 cumferential lamellae, interrupted by numerous very crude Haversian systems 

 of the (la) and (lb) differentiations. The band forms nearly the whole width 

 of the wall of the bone. In the posterior wall the lamellfe are displaced by small 

 undeveloped Haversian systems and in the outer wall a narrow crescent of 

 Haversian systems of the (C) stage appears just external to the internal cir- 

 cumferential lamellae. 



Internal circumferential lamellae surround the medullary canal. Generally 

 the lacunae are long and narrow and the canaliculi are straight, but in the pos- 

 terior wall the lacunae are oval. The bone shows the twofold division. 



Tji^e I-III, la, lb, C. 



femuh of putorius vulgaris. weasel. (^r. med. coll. 



Pl. 9, Fig. 179. Syx. T\I!. \ 



Antero-posterior diameter of the bone, 1..") nnii.; laleral, 2 mm. 

 Antero-posterior diameter of the medullary canal, 1 mm.; lateral, 1.5 mm. 

 The medullary canal contains a very Ihiii layer of mai^row around the walls 

 of the bone. Medullarv index, 62%. 



