LAHILLE: NOTA SOBRE EL CHENOfJASTER HOLMBERGI. 475 



Total leiigth 65 'fa inches. 



Lenfíth of head Jii 'l-j — 



Height of the body 1<> — 



Thickness at the pectorals 10 — 



Breadth between eyes <> — 



Diameter of the eye 1 — 



Length of pectoral 11 — 



Longest dorsal spine H — 



Height of sof t dorsal 5 '/< — 



Height of anal 3 'M — 



The skeleton resembles mueh tliat of a Thi/nnus. However, the 

 vertebrae are of a less fií-m texture, somewhat porous, less deeply 

 sculptured and lacking the high median lateral ridge whieh is so 

 conspieuous on the centrum of the vertebra of a Tunny. The num- 

 ber of vertebrae is twenty-tvvo or tv\enty-three in the abdomijial, 

 and twenty-oiie in the caudal división. 



None of the posterior caudal vertebrae are raised into the ele- 

 vated ridge of the Tunnies. The arrangement and form of the 

 neural, haemal, iiiternenral, and interhaemal spines are as in Thyn- 

 nuf!, but all are more slender, as are also the ribs and floating ribs. 

 «Foramina inferiora» ' seem to be present in the zygapophysis of 

 the sixth to thirteenth caudal vertebrae. The haemapophyses of 

 the middle and posterior abdominal vertebrae coalesce to form a 

 wide haemal canal, but whilst in Th¡jnnus the ribs are suspended 

 from the extremities of the greatly prolonged haemapophyses of 

 these vertebrae, they are, in this genus, attached to the base of the 

 apophyses. The neural spines of the seven posterior abdominal 

 vertebra do not bear interneurals. 



The skuU differ considerably in having a high crest developed 

 along the whole length of its upper surface, but in other respects 

 shows the closest agreement with that of the Tunny. 



See Lütken, Vidensk. Selsk. Skriv xii. 1880. \>. 473. 



