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SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



vol. 35 



The bone belongs to tbe same series as the foregoing. 

 The medullary canal is full. Medullary index, 44%. 



Structure. — The section is composed of wide external and internal lamelhe 

 with a central ring of Haversian systems. The enclosing horseshoe-shaped 

 band of lamellae is clearly marked. It is fairly uniform in width, and inter- 

 rupted by crude Haversian systems of the (la) differentiation. Around the 

 medullary canal is a wide ring of lamellae of varying widths. It is widest in 

 the inner wall and interrupted by a few incomplete Haversian systems. Be- 

 tween these two bands of lamellae is a narrow middle ring of Haversian sys- 

 tems and inter-Haversian lamellae. The lacunae are oval and long and their 

 canaliculi are long. 



Type I-III, la, C. 



RIGHT FEMUR OF AN ADULT EGYPTIAN. NO. 256481(d), U. S. NAT. MUS. 



Pl. 28, Fig. 3G7. Syn. Tab. IX 



Antero-posterior diameter of bone, 18.5 mm. ; lateral, 17.5 mm. 

 Antero-posterior diameter of medullary canal, 9 mm. ; lateral, 8 mm. 

 The medullary canal is full. Medullary index, 28%. 



Structure.- — The bone is surrounded by a lamellar ring, within which are a 

 few Haversian systems of the (la) and (C) differentiations. The ring is sep- 

 arated by concentric canals into laminae. 



The medullary canal is surrounded by a wide band of lamellae with long 

 lacunae and straight canaliculi, which in the inner wall rather abruptly widens 

 into a semicircular area of laminae occupying nearly the whole thickness of the 

 wall. The lamina' are interrupted by numerous Haversian systems of the (la) 

 differentiation. Between these two bands is an irregularly shaped central ring 

 of Haversian systems and inter-Haversian lamellae. The lacunae are long and 

 narrow and their canaliculi are long. 



Type I II III, la, 0. 



LEFT FEMUR OF AN ADULT EGYPTIAN. NO. 256481(a), U. S. NAT. MUS. 



Pl. 28, Pig. 368. Syn. Tab. IX 



Antero-posterior diameter of bone, 18 mm. ; lateral, 16 mm. 

 Antero-posterior diameter of medullary canal, 8 mm. ; lateral, 7 mm. 

 The medullary canal is full. Medullary index, 24%. 



The bone is very hard and brittle instead of chalky like the other femora 

 described. It is small and nearly round. 



Structure. — The posterior ridge, which is not very prominent, is composed 

 of well developed Haversian systems. 



