FAMILY CLUPID.E — HYODON. ',*(».") 



appears in our waters about the beginning of September, where it is often called the Shod 

 Herring. It has also the names of Thread Herring and Tliread-Jish, in allusion to its last 

 filamentous dorsal ray. 



{EXTRA-LBIITAL) 



C. ogUna. (Lesoeur, Ac. Sc. Vol. 1. p. o.'iO) Back almost straight; with three long-itudinal black 

 bands on each side. Anal fin hardly visilile. Dorsal not emarjjinate. Length 8 inches. Nac- 

 port Harbor. 



C. cepcJianiis. (Id. p. 3G1.) Pectorals reaching beyond the base of the vcntrals, which arc placed 

 anterior to the dorsal. Length eight to twelve inches. Delaicare and Chesapeake. 



C. ellipiicus. (KiRTLAXD, Zool. (_)hio, p. 195.) Hickory or Gizzard Shad. Undescribwl. Ohio 



R 



iver. 



GENUS HYODOX. Lesueur. 



Form of the preceding. Scales large, deciduous. Abdomen thin, trenchant, hut not serrated. 

 Dorsal and anal nearly opposite. Branchial rays eight or nine. Teeth minute and 

 curved, on,lhc jaws, tongue, vomer and palatines. Eyes very large. 



THE RIVER MOON-EYE. 



HyODON TERUlStS. 



PLATE XI.I. FIU. 130. — (CABI.NET OF THE LYCEU.M.) 



Hiodon tergiius. Lesueur, Journ. Acad. Nat. .Sc. Vol. 1, p. 3GG. 



H. tergissus, Moon-eyed Ilirrmg. KlKTL.iND, Zoology of Ohio, p. 170 and 103. 



Characteristics. Anal large and rounded anteriorly, with its posterior portion low. Lateral 

 line nearly straight. Dorsal margin concave. Length 9 inches. 



Description. Bod}' compressed ; the dorsal outline very slightly arched from above the 

 branchial aperture, thence descending to the tip of the snout, forming a slightly concave pro- 

 file. Scales large, caducous, membranous on their free edges, and with three radiating ele- 

 vated lines ; the radical portion striated in radiating lines, irregularly truncate on the iiiargin. 

 The scales ascend high up on the base of the caudal. Head small. Opercle with a slight 

 notch near its upper margin, which is filled up with a membrane. Eyes very large, and 

 nearly filling up the whole space between the angle of the jaws and the upper part of the 

 head. Snout in front descending almost vertically. Nostrils double, contiguous, patent; 

 both nearer the point of the jaw than to the eyes. Conic teeth in a single row above ; in 

 several rows on the lower jaw. Tongue with several series of teeth, of which the outer on 

 each side are largest. Teeth also on the vomer, and very minute ones on the jialatines. 



The dorsal iin with the first three rays simple, the fourth and liflh longest, the twelfth 

 shorter than the following; this fin arises shortly anterior to the anal. Pectorals \ ■ ;i long, 



Fauna — Part 4. 34 



