DR. J. MURIE ON THE ORGANIZATION OF THE CAAING WHALE. 279 
noticed a trachelo-mastoid, a longissimus dorsi, a sacro-lumbalis, with a slip supposed 
to be the homologue of splenius capitis, a levator caudz, a depressor caudz major, and 
depressor caudze minor. 
Notwithstanding amplitude of nomenclature, and recognition of two or more en masse 
or separate, the anterior divisions of the various observers present a certain harmony ; 
but there is less concord of opinion regarding the posterior tendinous parts and infero- 
lumbar region. Rapp and Stannius differentiate as transyersarius superior the com- 
pound tendinous enwrapping sheath of the longissimus and spinalis as described by me. 
But the latter, moreover, unites it with the anterior fleshy belly of my supracaudal, 
and iraces it forwards to the ribs, thorax, and neck, 7.¢. includes part of what more 
strictly is sacro-lumbalis and cervicalis ascendens. Carte and Macalister’s levator caude 
agrees partially with Rapp’s transversarius, and partially with Stannius’s caudalis 
superior. The latter muscle, again, is equivalent to Meckel’s flexor caudze lateralis and 
F. Cuvier’s levator caudz, one and the same with my supracaudal. None suggest the 
superior superficial terminal tendons, or aggregate fibrous investing-sheaths of the 
longissimus and spinalis dorsi, as the homologues of the levatores caude externus and 
internus of other mammals. Yet in every sense they are undoubtedly such, continuity 
with the dorsal fleshy masses being the only special deviation from their usual con- 
dition. The Cetacean supracaudal, again, offers homology in its posterior short slips 
with the intertransversarii caude of quadrupeds, its longer-bellied and more fleshy 
anterior moiety being occasionally in mammals almost separate from the intertrans- 
versarii caude, though not specially recognized as a distinct muscle. In Manatus, 
however, it is uncommonly well developed, and has been named by me lumbo-caudalis. 
The inferior depressor caudz of Meckel, depressor caudee minor of Carte and Macalister, 
caudalis inferior of Stannius, and his unnamed musculo-tendinous caudal bundles, cor- 
respond with the present infracaudal. 
As regards the depressor caude of Cuvier and Meckel, the depressor caude major of 
Carte and Macalister, this undoubtedly is Rapp’s psoas major &c. Stannius viewed it 
as composed of three divisions, equivalent to the dorsal muscles, and named by him 
respectively longissimus inferior, sacro-lumbalis inferior, and transversarius inferior. 
So far I agree with the latter, and therefore differ from Rapp, that the great sublumbo- 
caudal Cetacean muscle is not purely an ilio-psoas. This latter, I believe, as in 
Manatus, is all but aborted, certainly not recognizable. The homologue of the 
Cetacean sublumbar muscle, then, with its tendons and investing sheath, seems to me 
to be the sacro-coccygeus, whatever its significance as to the dorsal series. My infra- 
caudal may represent partly inferior intertransversarii caude or perhaps include infra- 
coccygeus. 
In default of being unable to determine with accuracy spinal insertions in Globiceps, 
I was more fortunate in Lagenorhynchus. In this genus the rectus abdominis tapers to 
a point at the fortieth vertebra, behind this intermingling with the caudal fascia. The 
