DR. J. MURIE ON THE ORGANIZATION OF THE CAAING WHALE. 277 
spinal column, a single, thick, massive tendon. Besides the foregoing, both longissimus 
and spinalis possess a deep series of long, narrow tendons, one to each vertebra, but 
mingled or bound together by interstitial fleshy fibres. It results that these dorsal 
muscles act upon every vertebra independently, whilst at the same time the motor 
power of the fibro-cartilaginous tail is derived from the lengthened and more powerful 
cords; for from these there extends backwards a firm, glistening fascia, spread over and 
incorporated with the deep tail-substance. ‘The latter, composed of closely packed 
parallel fasciculi, something of the consistence of the dorsal fin, traverse the thickness 
of the tail, and here and there have slits for the passage of the nutrient vessels. 
Supracaudal. The single muscle (or compound muscle, if so regarded) to which I 
give this appellation lies external to the last, along the narrow portion of the caudal 
vertebre, and on the upper side of the transverse process. Narrow in front, where 
fleshy, it widens somewhat and forms a tolerably thick fusiform belly, which again 
flattens and becomes tendinous. In its course it is attached partly to the vertebral 
bodies and partly to the transverse processes, sending off a special tendon to each of the 
latter. Posteriorly the flattened tendon lies against the sides of the bodies of the ter- 
minal vertebre, and ultimately is lost in the general expansion of the upper surface of 
the tail-flukes. For further remarks, see infra. 
Coming under the denomination of multifidus spine and rotatores spini, because of 
their position, origins, and insertions, are a great number of musculo-tendinous bundles, 
very apparent and well marked, but difficult individually to separate and define. These 
are still more numerous and closely packed together in Lagenorhynchus than in Globio- 
cephalus, in consequence of the number and approximation of the vertebre in the 
former. Stannius recognizes such a deep set of muscles in the Porpoise; and I can 
corroborate his observation in that genus. ‘Their general arrangement is by tendons 
from the dorsal metapophyses, and trending forwards and inwards are attached muscu- 
larly to the sides of the roots of the spinous process in advance of their origin. The 
most anterior one is fixed to the atlas. 
But there are besides a deeper layer of fascicles springing tendinously from the spines 
and dorsal arches, and these becoming fleshy are inserted into the transverse processes 
of the same vertebree—doubtless semispinales, as Stannius' names them in Phocena. 
He alludes, moreover, to another set of fasciculi, close to the last, and connected with 
the vertebral processes, but he has not named them. 
In the four-limbed mammals generally there are three, or at most four, muscles 
described as occupying the iliac region, viz. the psoas major, psoas minor, iliacus, and 
quadratus lumborum. But in Cetaceans, as most writers state, there is only one enor- 
mously large inferior lumbo-caudal muscle, which, at first sight, might be supposed 
either to represent the psoas magnus alone, or the psoas minor, iliacus, and quadratus 
lumborum incorporated along with it. Whatever relation exists, division at least is 
1 “ Muskeln des Tiimmlers,” Miill. Archiv, 1849, p. 30. 
2R2 
