NO. 3 COMPARATIVE HISTOLOGY OF FEMUR FOOTE 171 



all of the boue. A few senile systems appear. In the outer posterior wall 

 elongated systems occur. The Haversian systems generally are separated by 

 short lamellae with oval lacunae. The internal circumferential lamella;, of vary- 

 ing widths and irregularities, crossed by radiating canals and interrupted by 

 Haversian systems, surround the medullary canal. 

 Type I-III, la, C. 



RIGHT FEMUR OF A CHICAMA VALLEY INDIAN OF PERU. NO. 3, LT. S. NAT. MUS. 



Pl. 26, Fig. 348. Syn. Tab. IX 



Antero-posterior diameter of bone, 27 mm. ; lateral, 25 mm. 



Antero-posterior diameter of medullary canal, 16 mm. ; lateral, 11 mm. 



Medullary index, 35%. 



Sfnicture. — The external circumferential lamellae are incomplete. The cen- 

 tral ring constitutes most all of the section and is composed of large, small, and 

 irregularly sliaped Haversian systems, between which are some inter-Haversian 

 lamellfP with oval lacuna\ The lamella' are most prominent in the anterior wall, 

 and liere the systems are somewhat elongated in cross-section. 



The internal cii'cumferential lamell* are fragmentary. 



Type I-III, C. 



RIGHT FEMUR OF A CHICAMA INDIAN. NO. 1, U. S. NAT. MUS. 



Pl. 26, Fid. 34;). Syn. Tab. IX 



Antero-posterior diameter of bone, 26.5 mm. ; lateral, 31 mm. 



Antero-posterior diameter of medullary canal, 11 mm.; lateral, 16 mm. 



Medullary index, 27%. 



Structure. — The external circumferential lamellae are fragmentary. The 

 central ring constitutes nearly all of the section and is composed of Haversian 

 systems, large, small, and irregular. In the outer wall they have a more or 

 less elongated shape arranged concentrically and sej)arated by short lamellfe 

 witli oval lacmup. 



The posterior ridge is composed of Haversian systems with inter-Ha- 

 versian bone substance and oval lacuna;. 



A ring of internal circumferential lamella' sun'oiuids the medullary canal. 



Type III, C. 



LEFT FEMIIR OK A I'HICAMA INDIAN. NO. 4, U. S. NAT. MUS. 



Pl. 3(!, Fi(i. 350. Syn. 'J'am. IX 



Antero-posterior diameter of bone, 30 mm.; lateral, 28 mm. 

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

 Medullary index, 52%. 



