MUSCLES OF HEAD AND NECK. 17 
by Dobson to be ‘‘ very feeble” in Centetes; but in Potamogale is well developed. 
Dobson’s figure of the latter (Dobson, ’82-’90, pl. 9, st. h.) shows this muscle 
in nearly the same proportions as in Solenodon. 
The sterno-hyoid is the most ventral of the muscles of the throat. It arises 
from the inner or dorsal side of the second segment (mainly) of the sternum. 
This muscle is divisible into two elements, which, however, are so closely united 
in the mid-ventral line that the separation is not clearly defined until the invest- 
ing tissue is removed. The sterno-hyoid is broadly inserted into the ventral 
surface of the thyrohyal cartilage. 
The sterno-thyroid of each side is smaller than the corresponding sterno- 
hyoid, and arises just lateral to it. It passes forward along the side of the 
trachea to the thyroid cartilage, on to the side of which it is inserted by two 
short muscular branches. 
The crico-thyroid is represented by short muscles on each side, that pass 
obliquely from the cricoid to the thyroid cartilage. 
Beneath the mylo-hyoid on each side, from the symphysis for about 8 mm. 
posteriorly, arise the genio-hyoids. They are closely approximated medially 
and fill the space between the rami. They are inserted on the ventral side of 
the basi-thyrohyal. 
The genio-hyoglossus is as usual, a thin flat sheet of muscle, arising from 
the basihyals and radiating out anteriorly to the tongue. 
The trapezius muscles (Plate 4, fig. 1, a, c, d) arise along the mid-dorsal 
line from the vertebral spines to the occipital crest at the posterior edge of the 
skull, forming a broad thin sheet. They insert along the spine of the scapula 
beginning at about 15 mm. from its vertebral edge, forward for some 28mm. <A 
slight break indicates the division between the spino- and acromio-trapezius, 
but the latter and the clavo-trapezius are not clearly separable. 
The supracervico-cutaneus (Plate 4, fig. 1, b) arises from the mid-dorsal line 
of the posterior half of the neck and passes ventrally to become confluent with 
the broad tendinous sheet attached to the skin along the front edge of the fore 
shoulder. 
The rhomboideus arises underneath the trapezius, by two heads. The first 
consists of a single long band from the mid-dorsal portion of the neck from occiput 
to about halfway on its length. The second is a longer sheet from the last cervi- 
cals and first four or five dorsal spines. The muscle is inserted along the pos- 
terior inner border of the scapula from just below the angle along the entire 
vertebral margin. A similar partial division of this muscle was noted by Dobson 
