Cope.) 582 {March 7, 
” 
The statement ‘‘ maxillary wanting,”’ isin contradiction to the definition 
of the sub-class Hyopomata, which asserts the presence of those bones. 
Stannius* hag asserted the absence of the ‘‘oberkiefer’’ in the eel ; 
Giinther} describes their presence. As the absence of the maxillary bone 
would constitute a point of resemblance, if not affinity to the Elasmo- 
branchi, I have reéxamined my material to determine the homologies of 
the lateral dentigerous bone of the upper jaw of the eels. My specimens 
of species of’ the Colocephali include the following from the Hyrtl collec- 
tion: Myrus vulgaris ; Sphagebranchus rostratus ; Moringua rataborua ; 
Murena sp.; Murena unicolor; Murena sp.; Poecilophis polyzonus, 
and Gymnomurena tigrina. The pterygoid bone exists in a rudimental 
condition in the @ymnomurana tigrina, Myrus vulgaris, and one of the 
species of Mureena ; and whether lost in the preparation of the other crania 
or not, cannot be stated. In the Anguilla vulgaris the pterygoid bone is con- 
siderably larger, and extends to a point halfway between its base and the 
extremity of the muzzle. In the Conger vulgaris it extends still further 
forwards, reaching a transverse process of the anterior part of the vomer. 
No palatine bone appears. The premaxillary bone is not distinguished 
from the ethmoid in the Colocephali, nor in the Enchelycephali (Anguil- 
lide, etc.). It is quite possible, therefore, that the external dentigerous 
bone or upper jaw, in both of these orders, may be the palatine, and the 
maxillary be wanting. The family of the Mormyride appears to furnish 
the solution. In this group the structure and connections of the pterygoid 
bone are much as in Conger, and there are in addition distinct premaxillary 
and maxillary bones. It is clear that in this family it is the palatine, and 
not the maxillary bone, that is wanting. Similar evidence is furnished 
by the family Monopteride. The definition of all four of the orders, 
Jolocephali, Enchelycephali, Ichthyocephali and Scyphophori must, i 
therefore, embrace this character. The Jymnarchidse agrees with the 
Mormyride in this respect, and both families have the transverse process 
of the vomer which receives the pterygoid, as in the genus Conger.{ The 
supposed resemblance to the sharks presented by the Colocephali is then 
not real, and the question as to the point of affinity of the Ichthyotomi to 
the true fishes remains open as before, 
I now refer to the remarkable characters presented by the deep sea fishes 
of the family Eurypharyngide, as recently published by Messrs. Gill and 
Ryder.§ These authors find the characters of the skeleton so remarkable, 
that they think it necessary to establish a new order for its reception, 
which they call the Lyomeri. The definition which they give is the fol- 
lowing: ‘‘Fishes with five branchial arches (none modified ag branchi- 
ostegal or pharyngeal) far behind the skull; an imperfectly ossified skull 
articulating with the first vertebra by a basioccipital condyle alone ; only 
* Handbuch der Zootomie, Fische 1854, p. 76. 
} Catalogue Fishes, British Museum, vol, vili, p, 19, 
{ These transverse processes are enormously developed in Gymnarchus, 
? Proceedings U.S. National Museum, Novy. 1883, p. 262. 
