ORDER II. 
ANACANTHINI. ' 
The order of Anacanthinians is to include fishes whose anatomic structure is similar to tha 
of the preceding order, or Acanthopterians. The air bladder, when extant, wants, likewise, an 
air duct. We observe here, as in the preceding order, scales of both the cycloid and ctenoid 
types. The principal differences between the two orders consist in the absence of spiny rays 
to the fins of Anacanthinians, and in the ventral fins which may be wanting, or present and 
inserted under the thoracic belt or else under the throat. 
When the ventral fins are entirely wanting we have then the sub-order Apodes, whilst the 
sub-order Thoracici is composed of the remaining members of the order in which the ventral 
fins are more or less developed. 
Syn. — Jlnacanthinl, Mull, in Wiegrn. Arehiv fur Naturg. I, 1845, 130. 
The order .itself is composed of a portion of the “ Malacopterygiens sub-brachiens,” and a 
portion also of the “ Malacopterygiens apodes” of the Cuvierian system. 
SUB-ORDER I. 
APODES. 
The ventral fins in this sub-order are entirely wanting. It is composed of but one family, 
and that is represented along the Pacific coast by the Sand launce genus, and by OpMdion also. 
Syn. — Apodes, Linn. Syst. Nat. ed. X, 1758, 244.—Iconogr. Encycl. II, 1850, 204. 
There are now two sub-orders of Apodes in the class of fishes. The second is alluded to further 
on, and occupies a place in the order of Malacopterians. 
Eishes wanting the ventral fins are, moreover, met with elsewhere in the class, without, 
however, constituting groups of a higher value than genera, showing that the same organic 
structure may be variously subordinated in the ictliyic method. 
Family OPHIDIDAE, Bonap. 
The body is slender and elongated, compressed, provided with minute and inconspicuous 
scales. The ventrals, and sometimes even the pectoral fins, are wanting. The pseudo-branchiae 
exist, but, as already stated, the air bladder has no communication with the throat, and exhibits 
that curious vascular mesh-work peculiar to the fishes, in which that bladder is deprived of an 
air duct. 
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