DR. J. MURIE ON THE FORM AND STRUCTURE OF THE MANATEE. 147 
borum in every respect save size. The last superficial muscle ought possibly to be 
included among the dorsal series. It is evidently the homologue of a small muscle 
met with by Mivart and me in Galago crassicaudatus. In that animal it lies outside the 
origin of the levator caude externus, and comes from the lumbo-iliac fascia, and is 
inserted by tendons on the side of the root of the tail above the sacro-coccygeus. 
Doubtfully named by us', I here denominate it in the Manatee Iwmbo-caudalis. 1 do 
not recognize in Manatus any division of the infralumbar muscles agreeing with psoas 
and iliacus. If these are present they are indivisibly fused with the infra and sacro- 
coccygeus, and, besides, can have no limb-attachment. 
The great inferior loin- and tail-muscle of Cetacea Rapp regarded as a psoas; and he 
describes as costalis one of the outer dorso-caudal muscles. Meckel and others adopt 
a similar interpretation; but Stannius, in his myology of Delphinus, Phocena, and the 
American Manatee, opposes Rapp. He names in the former a sacro-lumbalis superior 
and sacro-lumbalis inferior, a longissimus superior and inferior, a. transversarius superior 
and inferior, a caudalis inferior, besides intertransversarii. He regards the Sirenian 
caudal muscles as nearly equivalent, more particularly laying stress on the so-called 
transverse muscles, these being below, as I presume, my sacro- and infra-coccygeus, and 
above the levatores. 
Of the deep muscles of the ventral surface of the neck, the longus colli, which is 
altogether broad and flat, may be reckoned as consisting of three triangular parts. 
These, however, are not very readily separable into distinct portions ; but the difference 
in direction of the fibres and attachments sufficiently define them. The first or pos- 
terior portion, homologous with the inferior oblique portion of higher mammals, covers 
the under surface of the transverse processes of the last two (fifth and sixth) cervicals 
and roots of the first two ribs. The second anterior or superior oblique slip of fleshy 
fibres arises widely from the ventral surface of the atlas, and is inserted narrowly and 
superficially tendinous into the rudimentary transverse process of the fifth cervical 
vertebra. The third inner and largest moiety of the longus colli has origin apically 
from the middle of the body of the atlas, and, widening on the surface of the neck, is 
attached to the inferior surfaces of the bodies of the succeeding cervical vertebra. 
The rectus anticus minor is seen on the outside of the rectus anticus major, and is 
fairly developed as a fleshy band whose origin is behind and beneath it cranially. It is 
inserted on the outer and under surface of the atlas. 
Considering the diminished extent of neck, the rectus anticus major is remarkably 
large and comparatively long. As in the Galagos and other aberrant Lemurs, it extends 
from the basilar process of the skull backwards to the bodies of the anterior dorsal 
vertebra. In the thorax it ends in two long, flattened, strong tendons—one to the 
* In Trans. Zool. Soc. vol. vii. pl. 2. fig. 3, lettered Tt.cd, it is regarded as perhaps an anterior prolonga- 
tion of the intertransyersarii caude ; but in the tail-dissection, pl. 6. fig. 25, where fully exposed, we leave it 
unlettered., 
