304 ADDITIONAL NOTES. 



The idea seemingly entertained by the author in the page 

 next to that last referred to, that the eel, by continued residence 

 in the sea, may acquire the size and be confounded with the 

 conger, does not accord with the best observations of naturalists 

 — most of them made since the publication of Salmonia. That 

 they are distinct species can hardly now be doubted, — even 

 generically they are now held to be distinct. The circumstance 

 that the number of vertebrae in the two differ — in the common 

 fresh- water eel being 116, and in the common conger 156, as 

 stated by Mr. Yarrell, — is a strong proof of their distinctness ; and 

 not less so is the fact (first noticed, I believe, by Sir John 

 Richardson,*) that the conger is destitute of scales. I have 

 examined its skin, in the same manner as the skin of the eel, for 

 scales, and neither before incineration nor after, have I detected 

 any, using a high magnifying power. 



The use of the minute scales of the eel, in all the species of 

 the genus Anguilla, may be considered a problem, comparing 

 them with the allied genera, as they are now constituted, which 

 are without scales, viz., conger, mura?na, and ophisurus, and 

 these again with the electrical fishes, the torpedo, gymnotiis and 

 silurus, in the skin of which no rudiments even of scales, in the 

 instances I have examined, can be detected. The common and 

 natural idea, that the scales of fishes are destined for defensive 

 armour, is not well accordant with these examples, excepting on 

 the supposition that the want of them in the electrical fishes is 

 compensated by the electrical organs of these fishes, and in the 

 others by the thickness and strength of their integuments : in 

 the cutis of the conger I have found on incineration a large pro- 

 portion of phosphate of lime. — J. D. 



(On the Food of the Shelley, page 264.) 



The author states that the lavaret, or shelley, is taken only 

 with nets ; that it feeds on vegetables ; and that he had never 

 found in the stomachs of those he had opened either flies or 

 small fishes. The first fish of this kind that I saw taken was 

 with a small fly : this was in Hawes Water. During nearly half 

 a century only two or three instances of its being so caught 



* " The Zoology of the Voyage of H. M. S. Erebus and Terror, Part vii. 

 — Fishes. By Sir John Richardson." 



