KAXMvICHI KISHraODYE: 



sui-fiice of the bone. This character, however, is not foiiud in Gramnudorcymis. 

 In the Cybiidas there is a pair of accessory crests Ijetween the temporal and 

 pterotic crests, except in Sarda and Gyrnnosarda. And this accessory crest 

 is situated rather near the pterotic crest, and is not so conspicuous as in the 

 ScoinbridcT?. 



The ahspheuoids are iDaired Ijjues, forming the anterior paii of the tioor 

 of the brain-cavity, situated ou lx)th sides of the ventral mediiiu foramen. 

 Generally ihey do not meet at the median line, but are separated by a large 

 foramen. The}' are Ixjunded by the frontals at the anterior end, by the 

 sphenotics at the exterior side, by the prootic and basispheooid at the 

 posterior end, and Iw the supraoccipital at the dorsal side in Gyrnnosarda 

 and Plecostei. The alispheuoids of the scombroid fishes never come in contact 

 with the prefi-outals, though MASTERiTAX (56) states that the alisphenoids of 

 the common Eraopean tunny extend fi'oin the prootics beliiud to the 

 prefrontals in front. In the Scombridaj the alisphenoids are a Httle longer 

 than broad, nearly fiat, and separated from the supraoccipital. In the 

 Cydiidffi the inner, anterior end of the alisjihenoids is more or less turned 

 downwai'd, and in Cyhhtm nijiltonimn (fig. A 2) and G. Icoreanum these bones 

 meet in the anterior median hue, and are firmlj- joined together over the i-oot 

 of the olfactory nerve. In the ThunnidiB (fig. A3) the inner mai'gin of the 

 alisphenoid is produced downward, and meets with tliat of the opposite side 

 in the median hne, to form a median ventral wall, separating the veuti'al 

 me ian foramen into two, the small anterior fcjr the olfiictory nerve, and the 

 large posterior for the optic. In the i^^.touwouidse the alisphenoids end in a 

 thick pointed process produced along the ventral side of the frontals, and the 

 posterior part is divided into two horizontal sheets. The ventral sheet ends 

 almost free ; but in Eutlajmms it meets .-with a si^ecial broad process of the 

 prootic. In the Cj'biidie and Plecostei the alisphenoid has a doi-sal liranch 

 ;it the anterior end. This doi-sal branch and the anterior ventral branch gi-asp 

 the thickened end of the fi-ontal. In the Scjmbridas the alisphenoids do not 

 reach the median uniting line of the fi-onbils ; but iu the Cybiidre and 

 Plecostei they reach the posterior end of the meilian uniting Une of the 

 frontals and are produced a little further anteriorly below the frontals. 



Tire pfU'asphenoid is a very long Ik me, nmning ueai-ly the whole length 



