372 G. B. GRASSI. 
phanus belong to that of Congromurena balearica; that 
under the name of Leptocephalus kefersteini are con- 
founded the larvee of various species of the genus Ophich- 
thys; that the Leptocephalus longirostris and the 
Hyoprorus messanensis are the larve of Nettastoma 
melanurum, and that the Leptocephalus oxyrhynchus 
and other new forms are larve of Saurenchelys cancri- 
vora, and that finally a new little Leptocephalus is the larva 
of Murena helena. 
The form known as Tylurus belongs to Oxystoma, of which 
we unfortunately know nothing more than a figure by Raffi- 
nesque. I have not been able to find the Leptocephalus of 
Myrus vulgaris, of which I have had only a single indi- 
vidual, in which the transformation was already far advanced. 
Neither have I found the Leptocephalus of Chlopsis bi- 
color, a very rare form, which is related to Murena and to 
Murenichthys. As the result of these observations, the 
family of the Leptocephalide has been definitely suppressed 
by me ; the various forms of that family are, in fact, the normal 
larvee of the various Murznoids. 
In regard to the greater part of the above-named species, 
the control has been threefold, namely : 
Firstly, anatomical. I have compared the various stages in 
all their structures, and have made the due allowance for the 
changes brought about by the metamorphosis at the close of 
larval life. 
Secondly, natural. I have found in nature all the required 
transitional stages. 
Thirdly, experimental. I have followed, step by step, the 
metamorphosis in aquariums. 
Therefore the hypothesis of Giinther that the Leptocephali 
are abnormal larvee, incapable of further development, must be 
rejected. All this is related by myself at length, with all 
historical details which concern the question, in a_ large 
memoir which is about to appear in the journal edited by 
Professor Todaro. 
Until now all these facts have been unknown, because nor- 
