DE. J. IVniEIB ON THE ORGANIZATION OF THE CAAING WHALE. 281 



distinctly marked in Globiceps, Grampus, and the White-beaked Bottlenose and Rorqual. 

 They undoubtedly resemble the interspinals superiores of these authors, but pass from 

 one chcvi-ou hsemo-spinal element to the adjoining. I prefer to designate them as 

 interhsemo-spinales, this term being more in accordance with morphological anatomy. 

 Stannius likewise differentiates, and names as M. interaccessorii a number of tendino- 

 fleshy fascicles which intervene between the one and the other accessory spinous processes 

 of the lumbar and dorsal vertebrae, in a longitudinal direction. These have not been 

 observed by me ; but I am inclined to regard them as intermetapophysales. 



3. Muscles acting on the Sterno-costal Framework. — The rectus abdominis in the 

 " Deductor " is striking on account of its vast thickness in the middle of the thoracic 

 region. Springing by a strong aponeurotic tendon from the manubrium, becoming 

 fleshy opposite the hinder border of the pectoral limb, it spreads out and covers a con- 

 siderable share of the hinder surface of the chest. By degrees naiTowing, it tapers 

 and apparently ends near the generative aperture, though a portion is continued on 

 towards the innominate bone, and by a tendon is fastened to the infracaudal fascia. 

 The attachments of the rectus in the Porpoise are nearly similar. Stannius' notes a 

 connexion with a tolerably strong aponeurosis, which proceeds from the pelvic region 

 to the transverse process of the nineteenth lumbar vertebra and general caudal fascia 

 investment. In the Piked Whale^ penniform insertions into the second to sixth ribs are 

 recorded. In Eisso's Grampus^ the muscular belly stops at the second rib, aponeurosis 

 continuing to first rib and sternum ; posteriorly it agrees with that of G. melas. 



The obliquus externus, internus, and transversalis are relatively weaker than the 

 preceding, though each is a gi-eat fleshy sheet. The former is attached to all the ribs 

 about their middle, save the three anterior ones, where the flbres spring near their 

 sternal ends. There are a few digitations with the serratus magnus ; posteriorly the 

 external oblique does not reach the pelvic bones. 



Both external and internal intercostals seem to possess considerable motor power 



over the ribs, judging from their full development. More particularly is this the case 



with the first external muscle, duly commented on by Stannius in the Porpoise. I also 



specially noted the presence of strong fieshy fibres corresponding to the triangularis 



stemi in G. melas {vide fig. 69) and L. albirostris. Under the head of musculi 



ossium sterni costalium, Stannius^ describes bundles in the Porpoise which appear to 



me identical with the triangularis. The Rostock professor likewise alludes to a 



sterno-costalis^ in the same animal. This double slip, with obliquely set fibres, has one 



part attached to the sternum and first rib and its cartilage, another between the first 



and second costse and sternal cartilages. I presume it agrees with what is now better 



known as the supracostal. MeckeP describes, but does not name, a muscle identical with 



the above in Cetacea, which he regards as assisting respiration in the diving animals. 



' L' <■• P- 19- ' Tbil. Trans. 1868, p. 224. » Journ. of Anat. vol. v. p. 134. 



' L. c. p. 38. ' L. e. p. 37. ' L. c. p. 190. 



