40 SMITHSOXIAX CONTKIBUTIONS TO KNOWLEDGE VOL. 35 



Structure. — The section is triangular iu shape and composed of lamellfp 

 with round and oval lacuna; and long canaliculi, divided into wide external and 

 narrow internal rings. A vascular canal is seen in the posterior wall. The in- 

 ternal ring foi-ms the internal circumferential lamella^. Twofold division. 



Type I. 



KIGHT FEMUR OF HYLA GRATIOSA. XO. E 40 14r, C. S. XAT. MUS. 



Pl. 2, Fig. 14. Syx. Tab. I 



Autero-posterior diameter of bone, 1 mm.; lateral, 0.8 mm. 



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



The medullary canal is full. Medullary index, 44%. 



Structure. — The section is composed of concentric lamellse with oval lacuniE 

 and bushy canaliculi surrounding the mediillary canal. A narrow lamina, not 

 parallel with the external or medullary surfaces, forms a complete ring around 

 the section. It approaches tlie medullary surface in the lateral wall and departs 

 from it in the anterior and posterior wall. 



Type I-Il 



EIGHT FEMUR OF DENDKOBATES TINCTORIUS. NO. E 14 36, U. S. NAT. MUS. 



Pl. 2. Fig. 1.5. Syn. Tab. I 



Autero-posterior diameter of bone, 0.6 mm.; lateral, 0.5 mm. 



Antero-posterior diameter of medullary canal, 0.2 mm. ; lateral, 0.2 mm. 



The medullary canal is full. Medullary index, 15%. 



Structure. — The section is composed of lamellte witli long, narrow lacunae 

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

 rings. Tlie internal ring forms the internal circumferential lamellse. Twofold 

 division. 



Type I. 



EIGHT FKMUR OF I/EPTOUACTYLUS ALKILABRIS. G 13 11, V. S. XAT. MUS. 



Pl. 2, Fig. Id. Syx. Tab. I 



Antero-])Osterior diameter of bone, 1 mm. ; lateral, 0.8 nnu. 



Antero-posterior diameter of medullary canal, 0.8 mm.; lateral, 0.3 mm. 



The medullary canal is full. Medullary index, 59%. 



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

 straight canaliculi, divided into wide external an<i narrow internal rings. The 

 internal ring forms the intenuil i-ircnuiferonlial laniella\ Twofold division. 



Type I. 



