S]/stemattc Position o/'Luvariis iinperlalis. 



373 



feature is also seen in Luvarus, and is well illustrated in 

 Mr. Waite's photograph. In the Scombridaj the vertebraj of 

 tlie caudal peduncle are square and have bioad flat neural 

 and hsemal spines, which are directed horizontally backwards, 

 so as to embrace the succeeding vertebrae above and below, 

 and the vertebise between the procurrent caudal rays are 

 greatly and progressively shortened. A similar condition 

 obtains in Luvarus ^ in which, however, the first vertebra of 

 the caudal peduncle is only half as long as the one preceding 

 it, but otherwise normal ; it is succeeded by two square ver- 

 tebrae, as in the Scombrida3, and between the last of these 

 and the hypural there is an extremely siiort vertebra. Tiie 

 sessile blade-like ribs exactly resemble the sessile anterior 

 ribs of a Thunnus ; epipleurals are absent. 



The pectoral arch is remarkable for the large size of the 

 post-temporal and for the fact that there is no supra-clavicle, 

 which may be regarded as having disappeared or as being 



pr-f- 



psp. pro. 



Greater part of Skull of Luvarus imperialis. 



so., supra-occipital; epo., epiotic; pfte., post-temporal; pa;-., parietal; 

 sq., squamosal; fr., frontal ; pr/., prefrontal ; ptf., postfrontal ; psp., 

 parasphenoid ; pro., prootic ; bo., basioccipital ; vert., centrum of 

 tirst vertebra. 



represented by the lower part of the post-temporal. The 

 post-clavicle is small, the clavicle, scapula, coracoid, and 

 pterygials exactly like those of Thunnus. Tiie pelvic bones 

 are completely united, but do not diverge posteriorly at the 

 vent, as has been erroneously stated. The vent is surrounded 

 by a cartilaginous ring, to which is joined the pelvis ante- 

 riorly and the bone formed by the united anterior interhsemals 



