NO. 3 COMPARATIVE HISTOLOGY OF FEMUE FOOTE 39 



EIGHT FEMUR OF HYLA EVITTATA. NO. E 55 17, TJ. S. NAT. MUS. 



Pl. 2, Fig. 10. Syn. Tab. I 



Antero-posterior diameter of bone, 0.5 mm. ; lateral, 0.2 mm. 



Antero-posterior diameter of medullary canal. 0.4 nmi. ; lateral, 0.1 mm. 



The medullary canal is full. Medullary index, 104%. 



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

 and long canaliculi, divided into wide external and narrow internal concentric 

 rings which surround the medullary canal, a twofold division. 



Type I. 



RIGHT FEMUE OF HYLA CINEREA. XO. 13095, U. S. NAT. MUS. 



Pl. 2, Fig. 11. Syn. Tar. I 



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



Antero-posterior diameter of medullary canal, 0.5 mm. ; lateral, 0.4 mm. 



The medullary canal is full. Medullary index, 14%. 



Structure. — The section has a long posterior process, the central position 

 of which, from the medullary canal to the tip, is occupied by bone substance 

 with a few oval lacimse and branching canaliculi. The body of the section is 

 composed of lamellae with oval lacunae and straight canaliculi. A narrow ring 

 of internal circumferential lamellae surrounds the medullary canal. The section 

 shows a twofold division. 



Type I. 



RIGHT FEMUR OF HYLA REGIL.LA. NO. E 62 39, U. S. NAT. MUS. 



Pl. 2, Fig. 12. Syn. Tab. I 



Antero-posterior diameter of bone, 1 mm. ; lateral, 0.9 mm. 



Antero-posterior diameter of medullary canal, 0.5 mm. ; lateral, 0.5 mm. 



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



Structure. — The section is composed of lamelte with oval lacunfe and long 

 canaliculi, divided into wide external and narrow internal rings. The internal 

 ring forms the internal circumferential lamella?. Twofold division. 



Type I. 



'eight femur of HYLA SQUIRELLA. NO. E 51 2, U. S. NAT. MUS. 



Pl. 2, Fig. 13. Syn. Tab. I 



Antero-posterior diameter of bone, 0.8 mm, ; lateral, 0.5 mm. 

 Antero-posterior diameter of medullary canal, 0.5 mm. ; lateral, 0.4 mm. 

 The medullarv canal is full. Medullary index, 92%. 



