436 ALLIS. [Vou. XIV. 
maxillaries, or of the nasals, as Huxley was inclined to think, 
their relations to the septomaxillaries must be of secondary 
origin, due to the great lengthening of the snout. 
In the Cyprinidae and Characinidae the ethmoid is a median 
bone. In the Cyprinidae it is said by Sagemehl (No. 37, p. 
497) to lie ventral to the anterior ends of the frontals. In the 
Characinidae (No. 36, p. 30) one is led to suppose that it has 
the same relative position to those bones, although this is not 
definitely said by Sagemehl to be so. In none of these fishes 
is the bone traversed by any portion of the lateral canals, and 
no intimation is given by Sagemehl of any lines of surface sense 
organs in relation to it. Such lines may, nevertheless, exist, for 
Sagemehl in his investigations took noaccount of them. In both 
the Cyprinidae and the Characinidae, the ethmoid, according to 
Sagemehl, is either partly of primary origin or has acquired 
more or less intimate primary relations to the chondrocranium. 
In Scomber, Dr. Dewitz finds a median ethmoid, and it has 
the same relation to the frontal bones of the fish that the 
ethmoid has in the Cyprinidae and Characinidae; that is, it lies 
wholly ventral to them. The bone, in Scomber, is certainly in 
largest part, if not entirely, of primary origin, and, as might 
have been expected, Dr. Dewitz has been wholly unable to find 
any trace whatever of pit organs in relation to it. 
These several facts all seem to indicate that the so-called 
ethmoids of Amia and Salmo, and bones 2 of Esox, which I 
consider as the ethmoid of that fish, are not the homologues of 
any part of the ethmoid of Scomber. Other facts, which will 
be given below in treating of the premaxillary bone, indicate 
that they are also not the homologues of any part of the 
ethmoids of the Characinidae and Cyprinidae, but this is much 
less certain than in the case of Scomber. In the Cyprinidae, 
in particular, the ethmoid has, according to Sagemehl, two such 
well-marked components that the superficial one, notwithstand- 
ing its position internal to the frontal, may be, as Sagemehl 
states, the homologue of the bone of Amia. 
The antorbital bone (ANV7) of Amia is a long bone, the ante- 
rior end and anterior part of the lateral edge of which rest upon 
the dorsal surface of the premaxillary, immediately above and 
