188 SMITHSONIAN CONTBIBUTIONS TO KNOWLEDGE VOL. 35 



Structure. — The external circumferential lamellae are fragmentary. The 

 central ring is composed of large, small, and irregularly shaped Haversian sys- 

 tems, most of which sliow marked degrees of senility. Some are black and 

 partly gone and others liave entirely disappeared, leaving spaces. The internal 

 circumferential lamella? are fragmentary, appearing only here and there. 



Type III, C, senile. 



LEFT FEMUR OF A WHITE MALE. NO. 162, MED. DEPT. NOETHWESTEBN UNIV. 



Pl. 30, Fig. 384. Syn. Tab. X 



Antero-posterior diameter of hone, 25 mm. ; lateral, 29 mm. 



Antero-posterior diameter of medullary canal, 13 mm. ; lateral, 15 mm. 



The medullaiy canal is full. Medullary index, 35%. 



Structure. — The external circumferential lamellae are fragmeutarj'. 



The central ring is composed of Haversian systems of various shapes and 

 sizes with round and oval lacunte and bushy and straight canalieuli, many of 

 which are senile. 



The internal circumferential lamellae with long, narrow lacuns" and straight 

 canalieuli surround the medullary canal. 



Type III, C, senile. 



EIGHT FEMUK OF A WHITE MALE. NO. 244, CR. MED. COLL. 



Pl. 30, Fig. 385. Syn. Tab. X 



Antero-posterior diameter of bone, 35 mm.; lateral, 30 mm. 



Antero-posterior diameter of medullary canal, 17 mm. ; lateral, 15 mm. 



The medullary canal is full. Medullary index, 32%. 



Structure. — Slight remains of the lamellar horseshoe are found on both 

 sides of the posterior ridge. 



The external circumferential lamellje are fragmentary. 



The central ring constitutes most all of the section, and is composed of 

 Haversian systems with many senile changes. 



The internal ciivuinferential lamellae fmiu a narrow fragmentary ring 

 around the medullary canal. 



Type III, C, senile. 



RIGHT FEMUR OK AN EAST INDIAN. NO. 223, CB. MED. COIA,. 



Pl. 30, Pig. 386. Syn. Tab. X 



Antero-posterior diameter of bone, 29 mm.; lateral, 24 mm. 

 Antero-posterior diameter of medullary canal, 16 miiL ; lateral, 12 mm. 

 The medullary canal is full. Medullary index, 38%. 



