210 CLASSIFICATIOX OF FISHES. 



among all the genera of this order we yet know. The 

 plates of tlie body, again^ although of such excessive 

 hardnesS;, appear^ from the figure^ to assume the form 

 and imbricate disposition of true scales ; and this struc- 

 ture is again at variance with all the other Plectognathes. 

 Nevertheless^ these deviations in an extreme aberrant 

 type are not altogether insurmountable, under the cir- 

 cumstances of its possessing the pedunculated pectoral 

 and ventral tins of the ChironectidcB and the LopMdce, 

 joined with their small and almost vertical eyes — a 

 single ray (if we understand the description) to the 

 branchia — and the uncommon hardness of its covering. 

 It has an obvious relationship to the genera Lepisosteus 

 and Sudis among the SalmonidcE ; but whether this is of 

 analogy or affinity we know not. The preponderance 

 of its characters, looking especially at the imperfect de- 

 velopment of the branchia, appear to us to be towards 

 those of the Plectognathes ; but this must be consi- 

 dered and determined by others who have better op- 

 portunities of investigating the question. Presuming, 

 however, that Polypterus is actually related by affinity 

 to the SyngnathidcF and the LophidcE, it will be seen that 

 certain analogical characters would come out, rather 

 tending to strengthen this supposition. As we have not, 

 therefore, tested the order by itself, or by that of the 

 others in the class, we shall do so in the following table : — 



Analogies of the Plectognathes and the Orders of 



Fishes. 



Families of j„„7„„4„„ . Orders of 



Plectognathes. Analogies. i ^^^^j.^^ 



rThe most perfectly organised : thel 

 Balistidcz. \ types with spinal rays, and with vAcaN'Thopteryges. 



C thin membranes to the fins. J 



m.- j-j f Fins thick, fleshy; the rays soft and 7 TT.T .^«r.™,.„..r^„„ 



Chtronectid^. \ articulated. J J.Ialacopteryges. 



I^opliidcE. Body mailed : mouth with cirri. Cartilagines. 



Po/,,.../..(P). [^^t^^^f r„,^5af Lt;edrcula^S:] P-cxeaNATHES. 

 Syngnathidie. Tail very long, attenuated. Apodes. 



It is needless to enter further into the first two of 

 these analogies, because they must be quite apparent to 



