14 The Cephalic Veins and Sinuses of Reptiles 
the nasal cavity the vein runs mesad above the cartilaginous roof of the 
nasal capsule and joins the vena nasalis dorsalis at the posterior end of 
the fenestra olfactoria. 
(2) Vena Prefrontalis (v. pf., Text Fig. 2).—This vein drains the 
prefrontal bone and the adjacent part of the orbital wall. It has its 
origin in the wall of the orbit, whence it runs mesad through the pre- 
frontal bone and joins the vena nasalis dorsalis below the junction of the 
sphen-ethmoid cartilage with the roof of the nasal capsule (tectum 
nasale). 
The system of the vena nasalis dorsalis is paralleled by a system of 
arteries and nerves, whose chief trunks, the ethmoid artery and nerve, 
pass through the fissura orbito-nasalis above the vena nasalis dorsalis. 
3. VENA FRONTALIS (v. fr., Text Fig. 2).—The vena frontalis drains 
the frontal and supraorbital bones and the adjoining skin. The vein is 
formed by two cutaneous roots, vena frontalis anterior and vena frontalis 
posterior, which run through the frontal bone and unite near the fronto- 
parietal suture. The trunk vein runs directly caudad under the lateral 
portion of the parietal bone and on the lateral aspect of the tania margin- 
alis of the chondrocranium. Caudal to the junction of the tenia margin- 
alis with the supraseptal cartilage (solum supraseptale) the vein dis- 
charges into the dorsal part of the sinus orbitalis. 
The vena frontalis receives two tributaries from the supraorbital 
region: | 
(1) Vena Supraorbitalis Anterior (v. so. a., Text Fig. 2).—This vein 
collects the blood from the rostral portion of the supraorbital region. It 
joins the vena frontalis near the fronto-parietal suture. 
(2) Vena Supraorbitalis Posterior (v. so. p., Text Fig. 2).—This vein 
receives blood from the posterior part of the supraorbital area; it joins 
the vena frontalis just anterior to the termination of the latter in the 
sinus orbitalis. 
The entire system of the vena frontalis is paralleled by a system of 
arteries and nerves which arise, respectively, from the arteria supra- 
orbitalis and the ramus frontalis ophthalmicus V. 
4. VENA SUBSEPTALIS.—The vena subseptalis is a short vein which 
begins at the posterior end of the cartilago paraseptalis of Gaupp, oo. 
It runs forward and dorsad a short distance and discharges into the 
sinus orbitalis through the ventral portion of the fissura orbito-nasalis. 
The vena subseptalis is formed on each side by the union of two veins, 
the vena subseptalis anterior and vena subseptalis posterior. The two 
ven subseptales anteriores have a common origin in a vena subseptalis 
