CHAPTER XXV 

 PAREIOPLIT.E, OR MAILED-CHEEK FISHES 



'HE Mailed-cheek Fishes. The vast group of Parei- 

 oplita (Loricati) or mailed-cheek fishes is charac- 

 terized by the presence of a "bony stay" or back- 

 ward-directed process from the third suborbital. This 

 extends backward across the cheek toward the preopercle. In 

 the most generalized forms this bony stay is small and hidden 

 under the skin. In more specialized forms it grows larger, 

 articulates with the preopercle, and becomes rough or spinous 

 at its surface. Finally, it joins the other bones to form a coat 

 of mail which covers the whole head. In degenerate forms it 

 is again reduced in size, finally becoming insignificant. 



The more primitive Pareioplita (napeia, cheek; oVAzr^?, 

 armed) closely resemble the Percomorphi, having the same 

 fins, the same type of shoulder-girdle, and the same insertion 

 of the ventral fins. In the more specialized forms the ventral 

 fins remain thoracic, but almost all other parts of the anatomy 

 are greatly distorted. In all cases, so far as known to the 

 writer, the hypercoracoid is perforate as in the Percomorphi. 

 There are numerous points of resemblance between the Cir- 

 rhitida and the Scorpanida, and it is probable that the Scor- 

 p&nidcB with all the other Pareioplitcs sprang from some per- 

 ciform stock allied to Cirrhitidcs and Latridida. 



Fossil mailed-cheek fishes are extremely few and throw little 

 light on the origin of the group. Those belong chiefly to the 

 Cottida. Lepidocottus, recorded from the Miocene and Oligo- 

 cene, seems to be the earliest genus. 



The Scorpion-fishes: Scorpaenidae. The vast family of Scor- 

 panidce, or scorpion-fishes, comprises such a variety of forms 



as almost to defy diagnosis. The more primitive types are 



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