of the Fishes of Cornwall. 3 1 3 



Pellucid Ophidium (Ophi'dium pellu^cidum Couch). 

 This fish (j%. 65.), of which I have seen four specimens, is 

 g^ 5iin. long, by half 



an inch deep; and 



^^^ ^^^^^>^»^» »^>/»^ » ^ ^^^*;^LP so transparent, when 



living, that the co- 

 lours of the vessel in which it was swimming, could be seen 

 through the thickest part of its substance. Head small, 

 sloping towards the mouth, compressed, under jaw shortest, 

 gill membrane attached, the opening near the pectoreil 

 fin. Eye large and bright; vent l|in. from the head; 

 at this point the body is deeper than along the abdomen, 

 it then gradually grows narrower to the tail. Pectoral fins 

 small, the dorsal fin beginning at about one third of the 

 length of the body from the head, the anal at the vent; 

 both joining to form the tail, as in the eel. Breast folded 

 from the thorax to the vent. Lateral line straight, having 

 along its course a row of black points ; along each side of the 

 abdominal plait, also, a row of points to the tail. The course 

 of the ribs is distinctly marked ; number of vertebrae counted, 

 150. The only opaque parts of this fish are the eyes; the iris 

 resembling a plate of silver, the black pigment surrounding 

 the posterior chamber also conspicuous ; convolutions of the 

 brain visible; no scales. One specimen differed from the 

 others, in having two bifid teeth projecting forward from the 

 under jaw; in proportion to the size of the fish they might be 

 termed tusks : in this specimen, also, the body was raised a 

 little immediately behind the head. 



Miscellaneous Notes. 

 Mode of Propagation in Eels. — The generation of eels has 

 been involved in extraordinary obscurity, notwithstanding the 

 attention which eminent naturalists have paid to the subject. 

 I have no doubt that the pearly white substance which lies 

 along the course of the spine of this fish (the situation of the 

 roe in most fishes) is the roe. Contrary to what is found in 

 most species of fish, this roe contains a large quantity of fine 

 oil ; so free from fishy flavour, as to be commonly employed 

 (at least, that found in the conger) in crusts and other culinary 

 uses in Cornwall. In the fish its use seems to be to protect 

 the delicate sexual organs from cold ; for these organs are 

 most developed in the coldest season of the year; and the 

 whole constitution of the eel is remarkably susceptible of cold : 

 it feels every change of temperature. There are no eels in 

 the Danube, nor in any of its tributary streams. The rivers 

 of Siberia, also, though large and numerous, are destitute of 



