No. 3.| MUSCLES AND NERVES IN AMIA CALVA. 555 
length, these two muscles arise as a single muscle, but they 
have their origin entirely from the front edge of the hyoman- 
dibular, the attachment to the parasphenoid being along the 
upper edge of the muscle and by connective tissue only ; 
that is, the attachment is from the side of the muscle fibres 
and not at their ends. This part of the muscle in these young 
specimens is a flat band lying close against the inner surface 
of the levator arcus palatini, and immediately external to the 
pseudobranch. It runs almost directly forward from its origin 
on the hyomandibular to the level of the front edge of the 
levator arcus palatini, where it turns downward and outward 
along the outer shelving surface of the metapterygoid, and there 
separates into two parts, a lower, posterior one, Ls?, and 
an upper, anterior one, Zms!. The former, Lms?, contracts 
near the front edge of A; to a slender tendon, and joins the 
large tendon A; Ao” at the point where that tendon is joined 
by the tendon of Zs3, with which it usually fuses and has the 
course and insertion already described. A secondary semi- 
tendinous connection of this tendon, similar to that of tendon 
Lms3, was sometimes found along the inner surface of A; do”, 
Lms*t, the upper, anterior division of the levator maxillae 
superioris, contracts near the front edge of Az to a flat, ter- 
minal edge and is inserted by a short, thin, fascia-like tendon 
on the inner surface of the tendon Az Aa! at its upper, anterior 
edge, internal to the coronoid process of the mandible and 
posterior to the hind edge of the splenial. Near its insertion 
the muscle is moulded against the front, inner edge of 42'”, the 
fibres of the two muscles ending at the same level, and the 
short, fascia-like tendon of Zs! appearing simply as a branch 
of, or slip from, the main tendon Az Ao’. It cannot be traced 
across this tendon as the tendons of Zs? and Lms3 were across 
the tendon A; do”. At its outer, anterior edge it is strongly 
attached by connective tissue to the dermis at the outer corner 
of the mouth, and at its inner, posterior edge it is connected, 
as already described, by a tendinous or connective tissue band 
with tendon A; Ao", the point of attachment to that tendon 
being at the angle formed by the crossing of the two tendons 
Lms3 and Lms?, where they join 4; Ao”. 
