2) 
M. spino-trapexius (tigs. 1, 4, and 5, s.t.), the caudal sector of 
the trapezial system, is separated by a considerable gap from the 
preceding, and, in the interval between them, portions of the 
Mm. latissimus dorsi and rhomboideus come into view. It arises 
from the tips of the spines of the seventh to the eleventh dorsal 
vertebre (inclusive), and-from the supra-spinous ligament, and it 
forms an elongated ribbon-like band, directed obliquely forwards 
and outwards, to be inserted into the post-axial lip of the scapu- 
lar spine, chiefly into a prominence of the same, which overhangs 
the post-scapular fossa. 
This strap-like muscle crosses the latissimus dorsi obliquely, 
and is supplied from the brachial plexus via the axilla, and 
posterior to the scapula, by a nerve, which also supphes the 
latissimus dorsi. 
This entire separation of the posterior segment of the trapezius 
sheet, both in origin and insertion, from the more anterior fibres, 
is quite unusual amongst marsupials; in fact, [ have neither 
observed, nor found any record of, such an arrangement in any 
other member of the order. 
The trapezius indeed in marsupials generally forms, as stated by 
Cunningham* for the three forms described by him, “an unbroken 
muscular sheet,” at least so far as the origin is concerned. Macalister,t 
however, reports, that in Sarcophilus “the part of the muscle corre- 
sponding to the root of the spine of the scapula was weak and tendin- 
ous, and nearly divided the fleshy part into an upper and a lower 
trapezius; however, a thin muscular margin near the spines of the 
vertebree saved it from this division.” 
In the Monotremes{ the posterior part of the muscle is quite 
separated from the anterior by a wide gap, the posterior part of the 
trapezius arising from the hinder ribs and vertebrze, and running for- 
ward to be inserted into the “ anterior’? or spinous border of the 
scapula near its basal end. (In Echidna also into the dorsal border.) 
A similar isolation of the posterior occurs in some of the Edentata, 
notably in Chlamydophorus$ and in the armadillos generally.|| It 
arises in Chlamydophorus from the anterior dorsal vertebrze, and is 
inserted into the scapular spine. 
The division is universal in the Insectivora,{ the hinder part (spino- 
trapezius) being inserted into the posterior end of the scapular spine. 
Mivart and Murie** describe the division also in the Agouti, where 
it is also figured by Cuvier and Laurillard,{} and it occurs in other 
rodents, e.g., the Rabbit. 
I find on dissection that the spino-trapezius in Talpa is innervated 
cut the axilla, as in Notoryctes. 
A tripartite division of the trapezius sheet exists in the cat,{{ in 
Ursus americanus,$$ and in Hyena,|\|| and in the Carnivora generally 
the spino-trapezius is differentiated. 
“iyv., page 2; {Xxix., page lot, ~xxxvil., page 23, and vi. Pl., 265. 
fig. 2, and xxxix., page 379, and lxii., page 12. §xxvii., page 234. || lvi., 
pace 92. ° I xxvi., page (20. ““* xl page ods. tT} vi. Pl.,-245. fb lxii., 
page 212, and lvi., page 93. §§ lvi., page 93, and vi. Pl., 81-2. |jl| vi. PL, 
129-30. 
