PROFESSOR WOOD ON THE NECK- AND SHOULDER-MUSCLES. 
95 
the trapezius. I have found the same arrangement in the Bonnet-Monkey (Plate X. 
fig. 12, e ). It is also the case, according to Mivart, in Cercopithecus sabceus (Proc. Zool. 
Soc. Jan. 10, 1865). 
In Ateles and Magot Meckel describes this muscle as double, having apparently con- 
nected it with the development of a cleido-occipital muscle, which is also found in these 
animals. This part of the supposed double muscle Meckel refers to the trapezius , with 
which he thus connects the muscle under consideration rather than with the levator 
anguli scapulae , as Cuvier does. 
In the Coati, Marmoset, Slender Loris, and Lemur macaco , according to Cuvier, the 
acromio-trachelien passes superficially over and across the front fibres of insertion of the 
trapezius to be inserted into the superficial aspect of the acromion process, constituting 
apparently a form transitional to that of its insertion in the Carnivora and Rodents, 
where we usually find a metacromial process developed downwards from the outer end of 
the spine of the scapula (see Plate X. figs. 15 & 16, z). By this means is provided a 
longer leverage for the muscle, enabling it to rotate powerfully the shoulder and anterior 
extremity outwards from the trunk, around the long axis of the scapula. In the Hedge- 
hog (fig. 18, e) the muscle is inserted superficial to the trapezius into the acromial pro- 
cess. It is totally absent in the Mole. In the Six-banded Armadillo ( Dasypus sexcinctus) 
Mr. Galtoh describes an acromio-basilar muscle taking origin from the lateral ridge of 
the supraoccipital bone and inserted into the metacromion process of the scapula (Trans. 
Linn. Soc. vol. xxvi. p. 527). This slip of muscle is, however, considered by Cuvier (plate 
259. fig. 2) and by Meckel (op. cit. p. 480) as the cervical portion of the trapezius , with 
which its origin from the supraoccipital bone would certainly ally it, while its insertion 
into a metacromial process would not be incompatible therewith. In the Orycteropus 
capensis, Professor Humphry describes this muscle, under the name of the cervico-humeral, 
as arising from the transverse process of the atlas, and inserted superficial to the trapezius 
into the spine of the scapula. In the Tamandua it reaches over and far below the sca- 
pular spine and trapezius. It is not figured in Cuvier and Laurillard’s plates of the 
Sloth, Anteater, or Armadillo. In those of the Lion and Panther it is represented as 
large, wide, and covered at its insertion by the trapezius ; but in the Bear, Striped 
Hyaena, Coati, Badger, Polecat, Genette, Dog, and Cat it passes superficial to the inser- 
tion of the trapezius to the metacromion process. In the Cat I have found it to become 
at its origin partially blended with the rectus capitis anticus major , and thus to arise, 
as we find it also in the Rabbit, partly from the basilar process of the cranium (see 
Plate XI. fig. 23, ee, and Plate X. fig. 13, e). In the Otter, IIaughton describes the 
muscle as subdivided into two parts, one attached to the outer or lower, and the other 
to the inner or upper end of the scapular spine (Proc. Royal Irish Acad. vol. x. pt. iv.). 
In the Seal it is also, according to Humphry, divided into two parts, one passing to the 
outer tuberosity of the humerus with the trapezius (thus extending still further its range 
of action as a swimming-muscle), while the other overlaps the supraspinatus, and is 
inserted into the angle of the scapula (op. cit. p. 299). 
