Macalister — On the Anatomy of Aonyx. 641 
dismemberment of the former, arising from the transverse process of 
the atlas, and inserted into the posterior fourth of the spine of the 
scapula. Indeed both the trachelo-acromial and this muscle bear the 
same relation to the levator anguli scapulae that the levator bears to 
the serratus magnus, all being fragments of the pleuro-scapular sheet, 
whose separateness depends on the relative and independent degrees of 
motion of the different regions. This lutrine muscle wq may call tra- 
chelo-scapalar ; it is less than the trachelo-acromial (0'17 : 0-10). 
The splenius capitis arises from the 1-3 dorsal, and 2-7 cervical 
spines, and is inserted below the sterno-mastoid into the par-occipital 
process and outer part of the occipital crest. Splenius colli is very 
weak. Serratus posticus superior extends from the upper 9 dorsal 
spines to the 1-1 1 ribs. Serratus posticus inferior is attached to 
the three lower ribs. Trachelo-mastoid passes from the 7th cer- 
vical, and 1-2 dorsal transverse processes to be inserted into the 
par-occipital, and has no tendinous inscriptions. Complexus arises 
from S-7 cervical transverse processes, and is attached below the 
occipital crest. Biventer cervicis arises from the 2nd-4th dorsal trans- 
verse processes, and extends to each side of the median line of the 
occiput, four tendinous inscriptions cross it in its course. 
The rectus capitis posticus major consists of two separate superposed 
laminae ; the other small nuchal muscles were regular ; the entire mus- 
cular mass for raising and drawing back the occiput was very large, as 
in all the Mustelidae, and weighed 3-40 ounces. The iliocostalis con- 
sists only of two parts — iliocostalis lambalis and iliocostalis dorsalis : 
there was no cervical prolongation. The longissimus dorsi, which had its 
usual double sets of tendons in the dorsal region, is continued up to the 
second cervical transverse process. The spinalis dorsi begins tendinously in 
the middle of the lumbar region, and is inserted by a tendon into each 
spine as far as the axis. Semispinalis formed a continuous lamella, and 
overlay in the dorsal region the multifidus spinse, which had no cervical 
representatives. 
The omohyoids were feeble and went from the basihyal to the 
fascia over the supraspinatus, along the upper edge of the scapula. 
Sterno-hyoid and thyroids were with difficulty separated, and were as 
usual traversed by an inscription. 
A strong transverse layer of muscle arose from the zygoma, and 
from the fascia behind it, passed transversely over the angle of the 
mandible, and was inserted into the median line. It underlay the 
rest of the platysma, of which it was a dismemberment, and was 
separated from the digastric by a thick layer of the cervical fascia. 
The digastric is a single thick muscle, traversed by an inscription, 
and arose from the paramastoid, passes forwards to be attached to the 
hinder half of the lower border of the mandible. The mylohyoid is 
strong, thick, and transverse,. The geniohyoidei are united to these, 
and to the geniohyo-glossi. The stylo-glossi were wide and short, 
and attached to the ceratohyals. The bilaminar oblique masseter was 
joined to the temporal, and both weighed 1-14 ounces on each side. 
