COMrARATIVi: SITDY OF SCOMBKOID FISHES. 40I 



cud, its upix^r snrtice flatteued aud naked, but the ojxarclcs are scaly. CautLil 

 jx-dniK-le roiUKk'd in cmss-section, liaviug uo latsral keel. A ijaii* of small keels 

 are found on eaiili side of the tail. Lateral line geuth' curved, wanting lujirk- 

 ihI Umdings or luuluLitious. Adijxjse eyelids present. Scales cj-cloid, often 

 ßneh' creuulated or more or less ctenoid at the jxjsterior niai'gin. Corselet in- 

 distinct. Tlie scales at the jxvitoral region have the same stnicture as those in 

 the leinainiug regions, but the former are only a little Lirger than the ktter. 

 Tlie former are not covered with a connective tissue mem1>rano. Postorbital 

 scales rather large, unequal in size. In the veuti-al half of the body, iwvs of 

 scales riui nearly parallel to the venti-al median hue of the caudal region. 



Mouth large with minute teeth. Tongue very small aud smooth. The 

 maxillary is almost entirely covered by the preorbital, f.ud the supplementary 

 Iwne at the ixstarior end is very small, slender and iusignificiiat. Prem^ixillaries 

 are very slender and weak. Gill-rakers very nuicerous, long, slender and much 

 compressed, with two rows of fine diverging i^aii-s of long denticles on the inner 

 side. Gill-liimellae very short at the angle of gill-arches. Branchiostegiü mem- 

 branes \ei'y bixxvd aud overlapping each other at the Symphysis. 



O^xircle short, aud notched at the posterior mai'gin. Subo^iercle vevy muTow. 

 Preo^jercle comimratively large, rounded aud expanded at the lower posterior 

 corner. Claviciikir ligament is inseiied at the posterior end of the exoccipibiL 

 Fins not well develo^jed. Interspinous lx)nes are weak and slender. Fin-mys 

 ai-e ti'aLsvei-sely articulated. Tlie second dorsal is lower tLiu the fii'st and the 

 two doisals are distinctly sepirated fi-om each other. The first spine of the fii-st 

 dorsal is shorter than some succeeding spines. The second dorsal aud the anal 

 are covered with small elongated scales. 



The abdominal cavity is ellipsoid in cross-section, wüth the longer diameter 

 vertical. Peritoneum generally black. Pylorus ascending. Pyloric coeca nu- 

 merous, arranged in mjiny longitudinal rows. They are rather large, opening 

 directly to the duodenum, and are looselj- conrected ^itli connective tissue 

 fibres. Alimentary canal long and folded. Tlie liver is a small tiiaugular 

 mas?, occuimug the left anterior comer of the abdomnial canty. Kidneys tliiu, 

 elongated and divided into tno before the i^haryngeal muscle, wliich is inserted 

 into the third or fourth vertebra, or into both. 



Skeleton tliin, but firm. Skull elongated aud the greater pai't of the fron- 



