CO.Mr.Vli.VTIVE STL'DY OF SCOJIDROID FI^IJIX 



361 



in length witli the roctuiii. Tlic nictuin is rolatively lout!; in Scomhcr too. 

 Tlic IjjiimTjuy l>etwet>n the snmll intestine and the rectum is indicnt«! by a 

 transverse ridge inside. lu the so called saunln-oid fishes the length of the in- 

 testine seems to hiwo but httle connection with the nature ef food, as voracious fishes 

 of the Cjbiidae have often a long int<^stine, folded several times, and fishes of the 

 Katsuwouidae, which feed on luediuna sized plankton, have a short, sh'aight mtes- 

 tine. RastrelUger which is a plankton-feed« :r 1ms a very long intestine, more 

 tlian 5 tunes as long as the length of the alxlominal cavity, usually the coloiu: of 

 the undigested ingrecheuts of food diflers in different tracts of the intestine. In the 



scombroid fishes the ahmeutaiy canal and genital and 

 urinary ducts open to a conuuon depression which is 

 very shallow and communicates to the exterior with an 

 elongated cleft. The anus, genital pore, and urinary 

 lX)re all open independently on respective papillae. Of 

 these the anus is tlie largest. The ixsterior wall of 



1, Srornher japomcus this cloaca-like space is more or less cLirker in colour 



2, Neothxmnus nia(ropterus 



Fig Jl External nper- ^'^^'^ *^® anterior. Wl\en we handle the viscera of a 

 J^VlSeihtTngTol^ t'"»°y' '"«1-« -1- 1««^ «tale, with naked hands the wet 



u^Jar?"oÄB°*ön' "he PO^i"!^ ^'^^^ ^^'^J' ^'^ ^ «''•t''™ l^P^^ ^e COntact 



respective papilla. occasious snifiU tiuuois of the skin. TIlis is probably 



due to the fonnation of ptomain. In the viscera of a stale fish we often find 

 small crystals on the external surface of the mass of the pyloric coeca. 



Liver (figs. 2, 3, 5, 6). The hver is a large brownish organ, generally 

 di\'ided into three lobes, and situated just behind the diaphragm, and covers 

 the anterior and ventral part of the stomach. In the Scombridae the Uve, 

 differs remarkably in form from the other allied fishes. It is a small, imdividedr 

 more or less triangularly pyramidal organ, with three ti'enchant edges. It is 

 situated at the left, anterior corner of the abdominal cavity. Tlie right hepatic 

 vein is found at the attenuated margin of the right, anterior comer. The 

 middle and right lobes are scarcely developed. In the Cybiidae we find three 

 lobes of the liver, but their respective size and form are variable. Grenerally 

 the right lobe which is scarcely developed in the Scombridae, is best deve- 

 loped, Init the left and middle lobes are poorly developed. In G/jmnasarda, 

 however, the left lobe is best developed. 



