50 SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE VOL. 35 



RIGHT FEMUB OF PTYCHOZOON HOMALOCEPHALUM GECKO. NO. 684 



AMER. MUS. NAT. HIST. 



Pl. 3, Fig. 44. Syn. Tab. II 



Antero-posterior diameter of boiie, 1 mm.; lateral, 0.8 mm. 



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



The medullary oanal is full. ]\Iedullary index, o3'/(. 



Structure. — The section is composed of concentric lamelte with long lacume 

 and long, straight canaliculi surrounding the medullary canal. Very little dif- 

 ferentiation appears. The section is uniform. 



Type I. 



eight femur of iguana tuberculata. amer. mus. nat. hist. 

 Pl. :1. Fig. 4.5. Syn. Tau. 1 1 



Antero-posterior diameter of bone, 3.5 unn. ; lateral, 3 mm. 



Antero-posterior diameter of medullary canal, 2 mm. ; lateral, 2 mm. 



The medullary canal is full. Medullary index, 61%. 



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

 and long, straight canaliculi surrounding the medullary canal. The posterior 

 wall is thickest and shows a column of oval laeunfE and their lamellae extending 

 from the medullary canal toward the external posterior surface. Very little 

 differentiation of stiucture a])pears. The section is uniform. 



Type I. 



left femur of varanus salvator. amer. mus. nat. hist. 

 Pl. 3. Fig. 4(5. Syx. Tab. TI 



Antero-posterior diameter of bone, 11 mm.; lateral, 10 nmi. 



Antero-posterior diameter of medullary canal, 7 muL ; lateral, 6 muL 



The medullary canal is full. Medullary index, 51%- 



Structure. — The section is composed of concentric lamella- with long and 

 oval lacunae and bushy canaliculi surrounding the bone, with the exception of 

 the posterior wall. The lamellae are partially separated into lamina' by con- 

 centric rows of long lacunae placed end to end. Numerous short canals, ])aral]el 

 to each other and radiating from the medullary canal, cross the lamelhp. Around 

 the canals are clear areas of bone substance crossed in many instances by fine 

 canaliculi. In the posterior and inner wall the concentric lamella? are displaced 

 by canals and oval lacunae with bushy canaliculi extending from the external 

 surface to the medullary canal. The canals mark the locations of future Ha- 

 versian systems. Fragments of lamella? sunound the medullary canal. In the 



