12 The Cephalic Veins and Sinuses of Reptiles 
The ventral part of the vena rostralis is connected by several short 
anastomoses with the sinus palatinus, the connecting veins passing through 
the dentary portion of the intermaxillary bone. The lateral portion of 
the vena rostralis gives rise, on each side, to a vena mavxillaris and a 
vena labialis superior (Text Fig. 2). 
The vena mazillaris, which is the more dorsal of these veins, passes 
under the external nasal opening and runs caudad for a short distance 
on the lateral aspect of the maxillary bone (v. ma., Figs. 2 and 3, Plate 
IT). At the level of the posterior end of the nasal vestibule the vein 
passes under the small sinus lateralis nasi (s. l. n., Text Fig. 2), with 
which the vein is connected by a short anastomosis. Continuing caudad 
the vein enters the maxillary bone, where it is joined by the vena later- 
alis nasi (v. 1. n.), which also drains the sinus lateralis nasi. Near the 
caudal end of the maxillary bone the vena maxillaris is joined by an 
anastomotic vein from the vena labialis superior, after which it emerges 
on the dorsal surface of the alveolar portion of the bone. Here it re- 
ceives the vena turbinalis inferior (v. t. 1., Text Fig. 2), which drains 
the lateral part of the turbinal prominence and the region adjacent to 
the posterior end of the ductus naso-lachrymalis. A little farther caudad 
the vena maxillaris enters the jugal bone, where it receives one or two 
anastomotic veins from the vena labialis superior. At the angle of the 
mouth the vena maxillaris escapes from the bone and forms a junction 
with the vena labialis superior, after which it bends dorsad, between the 
Jugal bone and the ramus maxillaris V, and discharges into the posterior 
part of the sinus orbitalis. 
In Lacerta agilis the vena maxillaris terminates in the sinus orbitalis 
and has no connection with the postorbital veins. 
The chief tributaries of the vena maxillaris are the sinus vestibuli 
nasi and the vena labialis superior, which are reserved for a separate 
description. 
(1) Sinus Vestibuli Nasi—The nasal vestibule, or anterior part of 
the nasal cavity of the lizard, is a passage of considerable length, which 
is lined with stratified squamous epithelium and surrounded, outside of 
the epithelium, by a thick spongy layer resembling erectile tissue. The 
sinus vestibuli nasi (s. v. n., Text Fig. 2; Figs. 2 and 3, Plate II) in- 
cludes the communicating blood-spaces of this spongy stratum. The 
blood-spaces are lined with a simple endothelium and seem to represent 
enlarged capillaries or veins. They are separated by trabecule com- 
posed of connective tissue and smooth muscle fibers (m., Fig. 5, Plate 
II), the latter arranged in a radial direction with reference to the nasal 
