FAMILY ANGUILLID^. 315 



GENUS OPHIDIUM. Cuvier. 



Head smooth. Body elongated, compressed. Dorsal, caudal and anal united. Scales small, 

 irregularly imbedded in the skin. Gill-openings large. Teeth on the jaws, vomer and 

 palatines. Two pair of barbels depending from the throat. 



THE NEW-YORK OPHIDIUM. 



Ophidium marginatum, 

 plate lll. fig. 169. — (state collection.) 



Cirrhous Ophidium, O. harbatum. MiTCHILL, Trans. Lit. and Phil. Soc. Vol. 1, p. 362, pi. I, fig. 2. 



Characteristics. Grey, with three dusky stripes along the body. Length nine inches. 



Description. Body elongated, eel-shaped, much compressed, tapering to an acute point. 

 Abdomen tumid. Surface smooth, with small cup-shaped elliptical distant scales (see figure), 

 deeply imbedded in the skin. These scales are radiately and concentrically striate, producing 

 a beautifully reticulated appearance under the lens ; the lai'gest are O'l in their largest dia- 

 meter, and none are arranged in a regular series. The disposition of the scales on the sur- 

 face, which i^ only evident after immersion in spirits, is very peculiar ; it has none of the 

 symmetry observed in all the other scaly fishes, and can scarcely be understood withoxit refe- 

 rence to the plate. An interrupted series of these scales is observed along the dorsal fin, a 

 short distance above its base. The lateral line arises above the upper angle of the branchial 

 aperture, follows the dorsal outline about a quarter of an inch below it, and becomes obsolete 

 about an inch from the end of the tail. Head smooth, scaleless, smaller than the anterior 

 part of the body. Snout prominent ; lower jaw shortest. Eyes large, 0" 3 in diameter, and 

 placed in the anterior third of the distance between the eye and the margin of the opercle ; 

 nearly their diameters apart. From the orbits to the snout, the facial outline is somewhat 

 concave, and then convex over the snout. Nostrils small, nearer to the end of the snout than 

 to the eyes. A broad fleshy process or extension of the skin,above the upper jaw. Branchial 

 aperture large, dilated above ; branchial rays seven. Tongue smooth, pointed. Bands of very 

 minute sharp teeth in both jaws, forming four to six series. Similar but smaller teeth on the 

 vomer and palatines. 



The dorsal fin commences gradually from a point two inches and two-tenths distant from the 

 extremity of the snout, and proceeds subequally, but insensibly diminishing from its height of 

 • 25 to its union with the caudal, which is pointed. The vent is placed 3 " 2 from the extremity 

 of the snout. Immediately behind it arises the anal, highest at its origin, but gradually decreas- 

 ing to the caudal. The rays of all the fins are very minute and delicate, so as to be enume- 

 rated with difficulty. In a space included within an inch, twenty rays were counted, which 

 would give a total for the three united fins of two hundred and twelve rays, of which seven- 

 teen may be assigned to the caudal, leaving one hundred and twenty to the dorsal and seventy. 



