142 
division of the tendon of the longitudinalis linguae muscle (fig. 24). 
At the point of insertion it is covered dorsally (fig. 29) by the small 
tendino-glossus (XXV) of that side. In action the hyomandibulari- 
glossus muscles assist the longitudinalis linguae. 
Figure 25 represents the dorsal aspect of the head after removal 
Throat Cavity Wall 
r \ 
leeren. 
\ 
' 
‘ 
t 
' 
' 
-External 
P Dovsal lining 
eprthel cum er ' 
buccal cavity. 
-FPT- 
Cavity oF LIU bifurcaked 
buccal funnel { A id pray Tendon. 
lin», al 
es: i -- Internal XE 
A ~~ External MI 
ps4 an 5 Cavıty u 
Na -- EX 
Re | ei --Canfy of 
al Ne, Threat 
"mu 
u 
: ~- il 
str . 
Fig. 20. 
Fig. 25 (x cire. 1). Dorsal aspect of anterior head region of Geotria australis 
after removal of skin. 
Fig. 26 (x cire. 50). Semi-diagrammatic section across one of the glands 
shown in figs 25—28. 
Fig. 27 (x cire. 1). The posterior dorsal carttlage has been removed, also the 
first two segments of the dorsal myotomes, the dorsal portions of the basilaris, and 
the sub-branchial musculature and other ventral structures anterior to the eyes on 
both sides, 
Fig. 28 (x cire. 1). Dissection showing external and internal pharyngeus muscles. 
Fig. 29 (X eirc. 1). Wall of the throat cavity wholly removed, except a strip 
on the right side, to expose the ventral layer of the pharyngeus and muscles 
XXII and XXV1. 
