ANATOMY OF B AL JEN OPTERA EOSTRATA. 
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the posterior cornu of the body of the os hyoides, crossing over the middle portion of 
the carotid artery and jugular vein. 
Scalenus anticus. — A round muscle ; it arose about 4 inches from the sternal end of 
the first rib ; its fibres ran upwards and outwards to be inserted into the anterior surface 
of the transverse process of the upper cervical vertebrae ; in its course it covered the 
axillary vessels, and the cervicalis ascendens passed along its external border. 
In Globiocephalus Svineval , Gray, the scalenus anticus was attached to the first and 
second ribs in front of their angles, and was inserted into the transverse process of the 
first cervical vertebra. 
Mastohumeral was pyramidal in shape; it arose from the transverse process of the 
anterior cervical vertebra}, and from the paramastoid process ; its fibres passed down- 
wards and outwards, converging to form a long round tendon that, towards the head of 
the humerus, became flattened prior to its insertion, which was into the anterior and 
internal part of that bone; from this point a tendinous expansion was continued in 
front of the humerus : this muscle probably represents the trachelo-acromial of quadru- 
mana and other mammals, somewhat similar to the levator claviculse which is often 
developed as an anomaly in Man ; a branch of the cervical plexus of nerves pierced the 
belly of this muscle. 
The sternohyoid muscle was long and flat, measuring 6 inches in length by 2 inches 
wide ; it arose from the upper border of the sternum, and passing upwards and outwards 
was inserted into the lower border of the body of the os hyoides. 
No sternothyroid muscle was found, although it exists in other Cetaceans. In the 
Globiocephalus Svineval it arose from the back of the inner part of the cartilage of the 
first rib, and was inserted into an angular line on the ala of the thyroid cartilage, the 
direction of its fibres being upwards and inwards, and in its course overlapping the 
carotid vessels. 
Thyrohyoid was a flat quadrilateral muscle ; it arose from the external and superior 
border of the thyroid cartilage, passing forwards and outwards to be inserted into the 
internal half of the superior cornua of the os hyoides ; in G. Svineval the origin of this 
muscle was from an oblique line on the ala of the thyroid cartilage, and its insertion 
was into the posterior border of the body of the os hyoides. 
The thyroid body was a large thin somewhat triangular or, rather, V-shaped mass 
enclosed in a fibrous capsule and about 6 inches in length, from before backwards, 
having its apex directed downwards and backwards towards the thorax, almost reaching 
to the bifurcation of the trachea ; its upper border or base corresponded to the inferior 
portion of the thyroid cartilage, and concealed a part of the lateral edge of the cricoid, 
being itself overlapped by the sternohyoid muscles. Large superior thyroid branches of 
the carotid artery were traceable into it, but no inferior thyroids were seen. In Globio- 
cephalus Svineval these vessels exist and attain a large size. 
Superior to the depressor muscle of the lower jaw and posterior to the articulation of 
that bone with the glenoid cavity, the portio dura of the seventh pair was situated ; this 
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