110 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



occipital and nuchal regions, which are armed with bony bucklers. 

 Marine cat-fishes. Species very numerous in the tropical seas. This 

 group has been divided into many genera, the value of which we are 

 unable to determine. Our common si^ecies is not a typical Arms^ but the 

 genus to which it belongs has not been properly defined. (From AH 

 gagora, the Bengalese name of the typical si)ecies.) 



a. Teeth all villiform, in a large rounded patch on each palatine and a small one on 

 each side of the vomer, these patches all distinct ; posterior buckler small. 

 {Ariopsis* Gill.) 



110. A. felis (Linn6) J. &. G.—Sea Cat-fish. 



Steel-blue, sides and belly silvery. Body rather elongate, not com- 

 pressed, tapering into the slender tail. Head subconic, depressed, flat- 

 tish above. Maxillary barbel nearly as long as the head. Mouth small. 

 Eye moderate, just in front of the middle of the head. Gill membranes 

 broadly united, partly joined to the isthmus, forming a narrow, free fold 

 across it. A small, bony, granulated buckler, broader than long, in front 

 of base of dorsal spine ; then a much larger nuchal shield with a me- 

 dian keel, and a still larger occipital shield with a median furrow. A 

 low fleshy keel along the back. Humeral i^rocess nearly half the length 

 of the pectoral spine. Caudal deeply forked, the upi)er lobe the longer. 

 Head 3| ; depth 5. D. I, 7, its spine not filamentous, serrate in front ; 

 P. I, 6; A. 16. L. 24 inches. Cape Cod to Florida; common south- 

 ward. 



{Sihirus felis Linn^, Syst. Nat. : Arius milberti Cuv. & Val. xv, 74 : Arius milherti 

 Gunther, v, 155.) 



111. A. eqwestris Baird & Girard. 



Similar, but with the spines higher and the maxillary barbels much 

 longer, reaching to the middle of the pectorals. Pectorals reaching to 

 last ray of dorsal. Dentition and character of the cephalic bucklers 

 undescribed. Head 4. D. I, 7 ; A. IG ; P. I, 0. Coast of Texas ; a 

 doubtful species. 



(Baird & Girard, Proc. Acad. Nat. Sci. Phila. 1855, 26; Giinther, v, 173.) 



58.— ^LrUKICIITTHYS Baird & Girard. 



Sea Cat-fishes. 



{Ailurichflnjs Baird & Girard, Proc. Acad. Nat. Sci. Phila. 1854,26: type SiJurjis mari- 

 nils Mitchill.) 



Body rather elongate, little compressed. Head depressed, broad 

 above. Mouth large, the upper jaw the longer. Teeth all villiform ; those 

 on the vomer and palatines forming a more or less perfectly crescent- 



* Ario])sis et Notarius Gill, Proc. Acad. Nat. Sci. Phila. 1663, 171 : type Arius milberti 

 C. & V. iArius; uipig, appearance.) 



