110 



SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



VOL. 35 



EIGHT FEMUR OF POTOS CAUDIVOLVULUS. KINKAJOU. AMER. MUS. NAT. HIST. 



Pl. 12, Fig. 218. Syn. Tab. VI 



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

 Antero-posterior diameter of medullary canal, 4.5 mm. ; lateral, 5.5 mm. 

 The medullary canal is full. Medullary index, 80%. 



Structure. — The section has three divisions. The external circumferential 

 lamellae form a narrow band around the anterior and lateral wall. Their lacunas 

 are oval and their canaliculi are straight. The central ring is composed of 

 Haversian systems and inter-IIaversian lamellae with oval lacunae and bushy 

 canaliculi. The ring forms the inner wall with the exception of the internal 

 lamella?. The internal circumferential lamellae form a ring around the medul- 

 lary canal. 



Type III, C. 



RIGHT FEMUR OF LUTRA CANADENSIS. OTTER. NO. 30191, AMER. MUS. NAT. HIST. 



Pl. 12, Pig. 219. Syn. Tab. VI 



Antero-posterior diameter of bone, 14.5 mm. ; lateral, 11 mm. 

 Antero-posterior diameter of medullary canal, 7 mm. ; lateral, 5 mm. 

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



Structure. — The external circumferential lamellae appear in fragments. 

 The central ring constitutes nearly the whole section and is composed of well 

 developed Haversian systems. In the posterior wall the systems are separated 

 by lamellae with oval lacunae and straight canaliculi. The internal circum- 

 ferential lamellae surround the medullary canal and form a wide band in the 

 outer wall. 



Type III, C. 



RIGHT FEMUR OF SIMIA SATYRUS. ORANG-UTAN. ( BORNEO.) NO. 154304, 



U. S. NAT. MUS. 



Pl. 13, Pig. 220. Syn. Tab. VI 



Antero-posterior diameter of bone, 20 mm. ; lateral, 30 mm. 

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

 The medullary canal is full. Medullary index, 41%. 



Structure. — The external circumferential lamellae are deficient in a portion 

 of the anterior wall, the Haversian systems of the central ring reaching the sur- 

 face at this point. The lamellae begin to increase in thickness as they pass 

 around the inner wall where they form nearly one-third of its width. They 

 then diminish in thickness as they reach the posterior wall, then slightly increase 

 in the outer wall, and finally disappear as they approach the anterior wall. In 



