608 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
from Scomber by the excessively long and numerous gillrakers (vas- 
trella), longer than eye, the mouth looking as if “ full of feathers,” by 
the compressed, deep body, and by the feeble dentition, the teeth in the 
Jaws being very minute, and the vomer and palatines toothless. 
Scomber kanagurta Cuvier and Valenciennes seems to be a second 
species of this genus and S. microlepidotus Riippell a third. Scom- 
ber loo (Cuvier and Valenciennes), another South Sea species, with a 
_ row of dark spots on the side, is also a species of Rastrelliger. It is 
distinct from Rastrelliger brachysomus and apparently from FP. kana- 
gurta also. The following osteological differences separating Rastrel- 
liger from Scomber have been worked out by Professor Starks: 
» The cranium in fastrelliger is less depressed than in Scomber, 
though it does not differ in the crests and ridges of the cranium from 
that genus. The epiotics appear to meet very broadly posteriorly, but 
close examination reveals a slender spur from the supraoccipital ex- 
tending down between them to the exoccipital suture. The top of 
the cranium in front of the oblique ridge that runs from the supra- 
occipital te the supraorbital rim is finely sculptured and thickened 
by a network of fine ridges where in Scomber the bone is smooth. | 
The foramen magnum forms a long tunnel of the exoccipitals, as in 
Scomber, and the condition of the exoccipitals over the basioceipital 
and their condyles is the same. 
The mandible and maxillary elements are much weaker than in 
Scomber. The premaxillary is a long slender bone from which the 
maxillary arches widely away, being attached to it only at each end; 
auxiliary maxillary is small. The most striking difference be- 
tween this genus and Scomber les in the arrangement of the lateral 
bones of the skull and the basibranchials. The pterygoid normally 
(as in Scomber) is attached along the anterior edge of the quadrate, 
at the upper end of which it bends at an angle forward to support the 
palatine; the metapterygoid is behind and a little above the quadrate. 
In Rastrelliger the metapterygoid is above and somewhat in front of 
the quadrate, and the pterygoid borders the entire front of both the 
quadrate and metapterygoid, turning at an angle at the upper edge 
of the latter. 
The basibranchials form a high, sharp, knife-like ridge, while the 
hypobranchials are deep and compressed and help to elevate the 
basibranchials still higher. The second and third superior pharyn- 
geals are joined into a single plate a little more firmly and completely 
than in Scomber. The branchial arches are crowded backward 
against and between the shoulder girdle, and all of the bones of the 
head give the impression of having been drawn downward and back- 
ward and compressed. 
