10 16 The Americaji Naturalist. [November, 
of fishes based on morphological facts, the salient differences between 
the Halosaurids and other fishes must be expressed by an ordinal, or 
at least a subordinal, designation. I do not see how the group can be 
referred to any of the existing orders with the characters we now assign 
to them, and for the present, at least, propose to isolate it as a peculiar 
order characterized by the following features contrasted with those of 
the generally recognized orders : 
Teleosts with the scapular arch constituted by the proscapula, 
postero-temporal and post-temporal, the post-temporal discrete 
from the side of the cranium, and impinging on the supra-occi- 
pital ; the hypercoracoid and hypocoracoid lamellar, and the fenestra 
or foramen in the upper margin of the hypocoracoid ; the mesocora- 
coid absent ; the actinosts normal ; the cranium with the condyle con- 
fined to the basi-occipital ; the opercular apparatus characteristic ; 
the preoperculum being entirely detached from the suspensorium rudi- 
mentary, and connected only with the lower jaw; the operculum 
normally connected ; the suboperculum enlarged and partly usurping 
the usual position of the preoperculum, in company with the suborbital 
chain, which is extended backwards toward the opercular margin ; jaw 
bones complete and normal ; palatines, entopterygoid, and ectoptery- 
goid normally developed ; the anterior vertebrae separate, and the 
ventrals abdominal. — Theo. Gill. 
The Notocanthid Fishes as Representatives of a Pecu- 
liar Order. — The genus Notocanthus has long been shifted from place 
to place without finding a natural resting-place. It was indeed long 
ago suggested by Dr. Gunther that " these fishes will, no doubt, have 
to be placed in a distinct order ; " but he has neglected to do so, or 
to give any reasons why he thought so. The facts now known, how- 
ever, warrant the isolation suggested, and the order may be defined 
by the following characteristics : 
Teleosts with the scapular arch formed by the proscapula and post- 
temporal (or posterotemporal), the latter detached from the sides of 
the cranium, and impinging on the supraoccipital ; the hypercoracoid 
and hypocoracoid coalesced into a single lamellar imperforate plate ; 
the actinosts normal ; the cranium with the condyle confined to the 
basioccipital (ill defined) ; the exoccipitals coalesced with the epiotics 
and opisthotics; the vomer obsolete; the opercular apparatus com- 
