COMPARATIVE STUDY OF SCOMBROID FISHES. 
461 
second vertebra the neural process and the lateral transverse processes aie re¬ 
markably large. The former is for the attachment of the muscle of the first 
dorsal, and the latter for the attachment of a pair of strong tendons from the 
centre of paired small cones of myotomes. First three vertebrae have a pair of 
strong ridges or pillars at the ventral side respectively. 
The centrum of the succeeding vertebrae is shaped like an hourglass, as 
longitudinal ridges are scarcely developed in them. Lateral keels are more or 
less developed in the majority of the caudal vertebrae, though many of them 
are not developed along the whole length of the side. In the precaudal ver¬ 
tebrae, ventral processes arise from the anterior end only, and they are united 
into a median rod, the epihaemal process of some length. At the distal 
end the rod is separated to parapophyses. The haemal arch and haemal spine 
are found in caudal vertebrae only. The epihaemal process is turned more or 
less forward in the caudal region as well, while the haemal processes are 
turned backward. Both neural and haemal processes from the vertebrae, with 
the exception of some caudal ones, are laterally compressed. Even in the first 
caudal vertebra, the epihaemal process is more or less turned forward and the 
process of that vertebra makes nearly a right angle with the haemal arch. 
The so-called trellis formed on the ventral side of the vertebral column is scar¬ 
cely developed in this genus. Spurious interneurals are found between the two 
dorsals. 
Epaxial cutaneous blood-vessels run near the lateral median line, and are 
united to segmental branches of both epaxial and hypaxial sides. These blood¬ 
vessels form sheets of the vascular plexus round the dark red portion of the 
lateral muscle, as the hypaxial cutaneous blood-vessels are atrophied as in the 
genus Euihynnus, and take no part in the formation of the plexus. The rod 
of the vascular plexus between the parapophyses in the precaudal region and 
in the haemal canal in the caudal region is thin and much degenerated. 
The dark red portion of the lateral muscle the chiai is broadest near 
the vertebral column, as the chief axial blood-vessels are far removed from 
the latter. A comparatively large portion of the lateral muscle is coloured dark 
red. Besides a concentric sheath of muscles round the strong tendon from the 
second vertebra, there is another smaller concentric sheath of muscles round an¬ 
other tendon on the external side of the anterior part of the cutaneous blood vessels. 
