100 The Cephalic Veins and Sinuses of Reptiles 
4. THECAGLOSSA.—Varanide. Monitor niloticus Hassl. Three strong 
muscles are present: m. constrictor ven jugularis interne, m. protrusor 
oculi, m. protrusor oculi accessorius. 
5. DIPLOGLOSSA.—Anguide. Anguis fragilis Linnaeus. Two muscles 
are present: m. constrictor ven jugularis interne and m. protrusor oculi. 
6. LEPTOGLOssA.—Lacertide.. Lacerta agilis Linnaeus, Lacerta mu- 
ralis Merr. The constrictor muscle and the m. protrusor oculi are pres- 
ent. The m. protrusor oculi accessorius is wanting. 
Tevide: Cnemidophorus sexlineatus Linnaeus. This species has the 
same muscles as Lacerta. 
7. ANNULATI.—A mphisbenide.  Rhineura floridana Baird. The 
essential parts of the moulting mechanism, protrusor and constrictor 
muscles and the facial sinuses, are wanting in this form. 
b. OPHIDIA. 
1. EPANODONTA.—T'yphlopide. Helminthopis (species?). The m. con- 
strictor vene jugularis interne is present. The protrusor muscles are 
both wanting. Corresponding to the rudimentary condition of the eyes, 
the sinus orbitalis is much reduced; other sinuses are abundant, especi- 
ally in the anterior part of the head. 
2. COLUBROIDEA.—Natricine. Tropidonotus natrix Gesner. The con- 
strictor muscle is present; protrusor muscles are wanting. Blood sinuses 
are well developed. 
Colubrine. Zamenis constrictor Linnaeus shows practically the same 
conditions as Tropidonotus. 
3. PROTEROGLYPHA.—H ydrophide. Hydrophis hardwickti Gray has 
remarkable blood sinuses, especially in the anterior part of the head. 
The constrictor muscle is strong; other muscles are absent. 
4, SOLENOGLYPHA.—Crotalide. Crotalus adamanteus Beauvais. The 
m. constrictor vene jugularis interne was easily found in a recently 
hatched specimen. | 
Viperide. Vipera berus Linnaeus has blood sinuses similar to those 
of Tropidonotus, indicating the presence of the m. constrictor ven 
jugularis interne. No attempt was made to find the muscle itself. 
ec. RHYNCHOCEPHALIA. 
Hatteria (Sphenodon) punctata Gray. 1 have made sections of the 
nasal vestibule of this species and find the spongy tissue well developed. 
The sinus orbitalis has‘ been described by Osawa, 98, as “ein grosses 
