734 B. W. KUNKEL 



horizontally backwards from the level of the upper margin of the 

 fenestra narina to the apex of the sinus nasalis posterior and at 

 the same time grows shallower. The paries nasi is of uniform 

 thickness throughout except in the region immediately posterior 

 to the groove on the exterior, which marks the position of the 

 concha. Here the wall of the capsule is thickened to form a 

 more prominent, rounded ridge on the inner surface. In front 

 of this thickening the paries nasi exhibits on its medial surface 

 a ridge (corresponding to the groove already mentioned on the 

 external surface) which supports a fold of the epitheUum of the 

 olfactory sac representing a rudimentary concha (fig. 11). 



The floor of the nasal capsule offers the most striking differences 

 from the conditions met with in other reptiles. The solum nasi 

 projects in front ventral to the fenestra* narina to form the pro- 

 cessus infranarinus, which thus limits the sinus externus below 

 and medially. Behind the fenestra narina the solum nasi is 

 continuous with the septum for a short space, and laterally bends 

 upward to unite with the paries nasi with an even curvature. 

 This portion of the solum nasi represents the lamma transversalis 

 anterior of Lacerta. Posterior to this portion the solum nasi is 

 separated from the septum by an elongated slit to which Seydel 

 has given the name foramen praepalatinum if .p. fig. 25). Behind 

 this foramen the floor of the capsule again unites with the sep- 

 tum. In this region the ventral margin of the septum inclines 

 strongly dorsally in a posterior direction. From the posterior 

 margin of the solum there projects posteriorly a short cartilage 

 paraseptalis which bounds the fenestra basalis medio-ventrally 

 and is separated from the septum by a narrow sinus paraseptalis. 

 Laterally the solum nasi at its transition to the paries nasi is 

 prolonged, as already mentioned, to form a short spout-like 

 process extending for a short distance posteriorly and supporting 

 the ductus naso-pharyngeus ventrally and laterally, which may 

 accordingly be called the cartilago ectochoanalis. The lateral 

 margin of this limits the sinus posterior below. 



The significance of that portion of the solum nasi which is 

 continuous with the septum between the foramen praepalatinum 

 in front and the fenestra basalis behind is difficult to understand . 



