116 The Cephalic Veins and Sinuses of Reptiles 
PLATE II. 
Fic. 1. Reconstruction from an adult Monitor niloticus, to show the rela- 
tions of the m. protrusor oculi, m. protrusor oculi accessorius and m. tempor- 
alis, as viewed from a medial direction. xX 8. Somewhat diagrammatic. 
B., bulbus; Bs., basisphenoid bone; Ept., epipterygoid bone (columella) ; 
Fr., frontal bone; Mm. ¢. s. 0., Mm. compressor sinus orbitalis; m. ¢. s. 0’., por- 
tion of m. compressor sinus orbitalis which enters the membrana nictitans; 
m. d. p. i., fascia from which the m. depressor palpebre inferioris takes its 
origin. In Monitor this fascia is separate from the fascia of the m. pro- 
trusor oculi. m. p. o.,m. protrusor oculi; m. p. 0. a@., m. protrusor oculi acces- 
sorius; m. t., m. temporalis; P. a., pila accessoria of chondrocranium; P?rf., 
' Prefrontale; s. o., sinus orbitalis; 7. m., tenia marginalis; v. 7. 7., vena jugu- 
laris interna. 
Fics. 2 anp 3. Transverse sections through the nasal vestibule of Lacerta 
agilis. Fig. 2 shows a section close behind the external nasal opening; Fig. 
3, a section through the posterior part of the vestibule. X 23. 
C., cartilaginous nasal capsule; Ima#., Intermaxillary bone; J. o., capsule of 
Jacobson’s organ; Maz., maxillary bone; N., nasal bone; Smz., septomaxillary 
bone; s. t., spongy tissue of nasal vestibule; s. t’., body of spongy tissue be- 
hind the external nasal groove, n. g., of Fig. 2; v. 1. s., vena labialis superior; 
v. mx., vena maxillaris; v. s. m., vena supraseptalis media. 
Fic. 4. Transverse section of Hydrophis hardwickii just behind the ex- 
ternal nasal opening. X 22. 
J. 0., Jacobson’s organ; m., bundles of smooth muscle fibers of the spongy 
tissue of the nasal vestibule; Smaz., septomaxillary bone; S. n., septum nasi; 
S. §., Sinus subnasalis. It opens above into a still larger sinus from which 
the vena maxillaris takes its origin. s. v. n., one of the blood spaces of the 
sinus vestibuli nasi; v. mx#., vena maxillaris; v. n., nasal vestibule. 
Fic. 5. Phrynosoma cornutum. Transverse section through the nasal ves- 
tibule close to the external nasal opening. In front of the section the 
vestibule bends laterad in the direction of the line s. t. X 21. 
g. n. e., glandula nasalis externa; m., smooth muscle fibers of the spongy 
tissue of the nasal vestibule; N., nasal bone; Prf., prefrontal bone; Smz., 
septomaxillary bone; S. n., septum nasi; s. ¢t., spongy tissue. The particular 
body of tissue indicated by the line lies directly behind the external nasal 
opening. 
Pram DIL: 
Fic. 1. Transverse section of Phrynosoma cornutum through the region 
of the m. protrusor oculi.  X 11. 
The section is somewhat oblique, the right side being more anterior than 
the left. 
Bs., basisphenoid bone; Bs. p., process of basisphenoid which gives rise to 
the m. protrusor oculi; m. b., m. bursalis; m. d. p. i., m. depressor palpebre 
inferioris; m. p. 0., m. protrusor oculi; Ps., parasphenoid bone; pit., pituitary 
