140 
Behind the posterior lateral cartilage portions of three other muscles. 
can be seen in this figure 21—the pharyngeus (XX), hyomandibulari- 
glossus (XXIT) and the hyo-hyoideus posterior (XIII) —which will be 
described later. Inserted into the lower ends of the styloid process and 
cornual cartilage, is the dorsal portion of one side of another small 
unpaired semi-tubular muscle, the hyo-hyoideus anterior (XJV), which 
extends across the mid-ventral line under and therefore outside of the 
large and also median hyo-hyoideus posterior muscle (see also figs. 19 
and 39). This small muscle aids the hyo-hyoideus posterior in action. 
Immediately behind the hyo-hyoideus anterior there lies on each side 
of the body a small slender paired muscle, the hyobranchialis (XV). 
This hyobranchialis is inserted dorsally into the lower end of the 
styloid process just behind the insertion of the hyo-hyoideus anterior, 
and passes ventrally and posteriorly to become attached to the median 
anterior end of the mid-ventral bar of the branchial basket skeleton. 
In action this small muscle compresses the pharynx in the region of 
the styloid process by elevating the ventral anterior part of the 
branchial basket. 
In figure 22 the branchial basket, gill-pouches and gill muscles 
have been removed, also the hyo-hyoideus anterior, hyobranchialis, 
hyomandibulari-glossus, hyoglossus, anulo-glossus, copulo-glossus rectus 
and rhombo-semianularis muscles and posterior lateral cartilage, in 
order to show the extent or position, as the case may be, of the hyo- 
hyoideus posterior, longitudinalis linguae and pharyngeus muscles. 
Three small muscles have also been removed anteriorly and the piston 
cartilage has been thrust forwards considerably as compared with its 
position in foregoing figures. The hyo-hyoideus posterior muscle (XJJJ) 
is, aS the figure shows (see also fig. 37), a large thick median com- 
pletely-tubular muscle which surrounds the anterior part of the big 
longitudinalis linguae muscle and the posterior part of its single mid- 
ventrally placed tendon (see also fig. 24). Anteriorly this tubular 
muscle is attached dorsally to the cornual and styloid processes on 
each side (see also fig. 24.) Somewhat posteriorly to the styloid process 
the muscle on each side of the body divides into upper and lower 
portions, the upper being continuous dorsally with the muscle of the 
other side just below the pharynx (respiratory tube), the lower being 
connected dorsally with the lateral fascia of the longitudinalis linguae 
muscle. Thus, as above stated, the hyo-hyoideus posterior completely 
envelopes the longitudinalis linguae. The function of this important 
