270 



Correspondence. 



Aberrant Group. 



r 



< 



i 



Normal Group. 



CYCLOPTE- 



RIDjE. 

 Discoboli, Cuv. 



2.echeneid^. 

 3. anguilim:. 



Apodes, Linn. 

 GADIDvE. 



Ventrals 

 throat. 



united under 



4. 



-1 



Gadides, Cuv. 



PLEURONEC- 

 TID^. 



Platessa, Cuv. 



Ventrals separate. 

 Ventrals none. 



Symmetrical body with ju- 

 gular ventrals far apart 

 from anal fin. 

 Body not symmetrical, hav- 

 ing the ventrals generally 

 Platessa, Cuv. a continuation of the 



v. anal. 



Many genera of these families of Pleuronectina are wanting, so that 

 I can only guess the above to be the natural series. Brotula and 

 Macrourus certainly shew the affinity of Anguillidse to Gadidse. The 

 affinity of Siluridae to Anguillidse is well known, so that we next pass 

 thus to the tribe CLUPEINA, which are Malacopterygian fishes, with 

 abdominal ventrals, i. e. the same as the group called Abdominales by 

 Cuvier. We are now more truly on the ground of your " Monograph on 

 Indian Cyprinidse," and I have little doubt of the following being really 

 and truly the families or stirpes of the tribe CLUPEINA, viz : — 



ATHYLACEN- 

 TERA. 



Intestinal canal not 

 furnished with 



1 



THYLACEN- 

 TERA. 



f 



1. SILURID.E. 



Silurides, Cuv. 



2. cyprinim:. 



Cyprinoides, Cuv. 



3. ESOCID.E. 



Esoces, Cuv. 



4. CLUPEID.E. 



<! 



Clupe;e, Cuv. 



No true scales on body ; repre- 

 senting PLAGIOSTOMI. 

 Body scaly, mouth slightly 

 cleft ; representing CYCLO- 

 STOMI. 

 Body scaly, mouth widely 

 cleft; representing LOPHO- 

 BRANCHII. 



No second dorsal ; represent- 

 ing OSTINOPTERYGII. 



Intestinal canal fur- ] 5. SALMONIDiE. Second dorsal adipose reple- 

 nished with caeca. L Salmonides, Cuv. senting STURIONES. 



I am often afraid of trusting myself to Mr. Swainson's method of 

 drawing analogies between things in themselves wide apart. A person 

 may reasonably doubt the legitimacy of any comparison between a 

 fish and an insect, or even between a fish and a bird ; because he may 

 attribute all such resemblances to the imagination, the objects being in 

 themselves so very dissimilar in every leading point of view. But no 



