NO. 3 



COMPARATIVE HISTOLOGY OF FEMUR FOOTE 



55 



RIGHT FEMUR OF SAUROMALUS. NO. J 40 6, U. S. NAT. MUS. 



Pl. 4, Pig. 61. Syn. Tab. II 



Antero-posterior diameter of bone, 3 mm. ; lateral, 2.5 mm. 

 Antero-posterior diameter of medullary canal, 1.5 mm. ; lateral, 1.2 mm. 

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



Structure. — The section is composed of concentric lamellae with oval lacunas 

 and straight canaliculi partially divided into concentric rings. A vascular canal 

 is seen in the posterior inner wall. A narrow ring of lamella?, with long lacunas 

 and straight canaliculi surrounds the medullary canal. 



Type I. 



RIGHT FEMUR OF GERRHONOTUS GRANDLS. NO. I 22 4, U. S. NAT. MUS. 



Pl. 4, Fig. 62. Syn. Tab. II 



A ntero-posterior diameter of bone, 1.5 mm. ; lateral, 1 mm. 

 Antero-posterior diameter of medullary canal, 0.4 mm.; lateral, 0.4 mm. 

 The medullary canal is full. Medullary index, 11%. 



Structure. — The section is composed of concentric lamellae with oval and 

 long lacunae and straight and busby canaliculi. Around the posterior and 

 lateral medullary surface is a crescent of basic bone substance with round 

 lacuna?, and bushy canaliculi. 



Type I. 



RIGHT FEMTTR OF PYTHON REGIUS. PYTHON. ( II 1 FEET IN LENGTH — ■ 

 DIED AT WASHINGTON ZOo) 



Pl. 4, Fig. 63. Syn. Tab. II 



Antero-posterior diameter of bone, 1 mm. ; lateral, 0.6 mm. 

 Antero-posterior diameter of medullary canal, 0.4 mm.; lateral, 0.3 mm. 

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



Structure. — The femur is rudimentary. The section is composed of lamelhc 

 arranged in a peculiar manner. In the anterior wall they are arranged con- 

 centrically around a semicircle with a short radius. In the lateral and pos- 

 terior wall the lamellae take a long curve from the medullary surface of the 

 anterior wall. The lacunae are round and the canaliculi are bushy. The anterior 

 wall is best developed. A narrow ring of internal lamellae with long lacunae 

 and straight canaliculi surrounds the medullary canal. 



Type I. 



