No. 3.] WUSCLES AND NERVES IN AMIA CALVA. 565 
and bound together. The curved line of these tendinous edges 
lies a little behind the symphysis of the hypohyals, and is concave 
forward, leaving a space in front of it, between it and the hypo- 
hyals, through which the branchiomandibularis passes. 
The anterior or inferior part of the hyohyoideus is somewhat 
divided into two portions or bundles, one arising from the bran- 
chiostegal rays, and the other from the shank of the ceratohyal, 
the division between the two portions being faintly indicated 
by surface lines. The fibres arising from the branchiostegal 
rays are the ones that pass across the middle line of the body, 
and enter into the tendon that lies on the opposite side of the 
head, while those arising from the ceratohyal usually pass 
directly forward into the tendon of their own side. The fibres 
arising from the branchiostegal rays are more or less separated 
into parallel bundles, closely held together by connective tissue. 
This condition is most apparent near the front edge of the first 
ray, and there gives to the muscle a stringy or striped appear- 
ance. These bundles have their origin in part from the front 
edge and under surface of the first ray, and in part they are 
continuations of more or less continuous cord-like muscles, 
which have their origin from parts beyond this ray, and form 
what Vetter has called in other fishes the superior part of the 
muscle. These muscular cords are wholly, and in places some- 
what widely, separated; they branch somewhat, and are alter- 
nately tendinous and muscular, the muscular portions lying, in 
every case, across the interspaces between successive rays. 
Throughout their course they are firmly held in connective 
tissue, which is closely attached to the inner or dorsal surfaces 
of the rays. The little muscular swellings, or bellies, lie most 
frequently directly in the course of the more or less continuous 
cord, but they may extend from one cord to another, or arise 
from the side of a cord in front, and be inserted on the inner 
surface of the next ray behind. Along the median or free 
edges of the rays, each cord forms a continuous line, but 
toward the edge of the ceratohyal the other arrangements 
prevail, the cords becoming somewhat crossed and interlaced ; 
while from the edge of the ceratohyal larger muscle bundles 
arise, which, running forward and outward along the inner, 
