COMPARATIVE STUDY OP SCOMBROID FISHES. 461 



second vertebra the neural process and the lateral transverse processes are rc- 

 luarkjxbly large. Tlie former is for the attachment of the muscle of the firet 

 dorsal, and the latter for the attachment of a pair of strong tendons froiu 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 scjircely devolojjed in them. Lateral keels are more or 

 less developed in the majority of the caudal vertebrae, though many of them 

 are not developed aloug 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 proc3SS is turned more or 

 less forward in the caudal region as well, while the haemal processes are 

 turned backward. Both neiu-al and haemal processes from the vertebrae, with 

 the exception of some caudal ones, are laterally compressed. Even in the first 

 caudal veiiebra, the epihaemal process is more or less turned forward and the 

 process of that vf-,rtebra 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. Spnrious interneurals are found between the two 

 dorsals. 



E^jaxial cutaneous blood-vessels run near the lateral median h'ne, and are 

 united to segmental branches of bjth epaxial and hjpaxial sides. These blood- 

 vessels form sheets of the vascular plexus round the cLirk red portion of the 

 lateral muscle, as the hypjixial cutiuieous blood-vessels ai-e atrophied as in the 

 genus Evihynnus, 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 fcir removed from 

 the latter. A comimratively large portion of the lateral muscle is coloured dark 

 red. Besides a concentiic 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. 



