BULLETIN OF THE UNITED STATES FISH COMMISSION. 433 
of far less importance than its congener. In our opinion Dr. Stein- 
clackner is quite right in regarding the Scomber pneumatophorus as iden- 
tical with S. colias. 
One of the specimens before us, collected at Block Island by Pro- 
fessor Seth E. Meek, shows a remarkable union of the characters of S. 
scombrus and S. colias , and is probably a hybrid between the two. It is 
13J inches in length. The following are its characters: 
Description of a supposed hybrid , scombrus colias. 
D. xii, i-10-iv ; A. i, 11— i y. The hindmost finlets are double, as is the 
case with S. scombrus . The ridges on its head*are in three parallel lines, 
= , as in scombrus , not ^ >- — ■, as in colias. Subopercle more ellip- 
tical than triangular. Posterior border of eye not covered with large ra- 
diating scales. Top of head, as in S. scombrus , without translucent area. 
About 20 small black specks or pores at base of preopercle, arranged in 
a single row. Coloring on the back in blotches, as in colias , rather than 
in stripes, as in scombrus. Sides mottled, much as in colias. No longi- 
tudinal groove between the dorsals. A black axillary spot. Snout 
more like scombrus than colias . Base of pectorals dark. Ventrals and 
pectorals short. Eye, 5 in head. Head, 4 in length to fork of caudal 
fin. Body robust, as in colias. Caudal peduncle round, as in colias , 
rather than depressed, as in scombrus. The following note was made 
by Professor Seth E. Meek, the collector : u September 16, Block Island. 
A peculiarly marked Scomber scombrus, only four finlets, no air-bladder, 
low, spinous dorsal, and markings of S. colias. Blackford thinks it is a 
cross between the two.” 
Genus II.— AUXIS. 
Auxis Cuvier, Regne Animal, ed. ii, 119, 1829 (rochei). 
Type : Scomber rochei Risso —Scomber thazard Lac6p&de. 
Etymology : afrgtq, a kind of tunny ; from auqco, to grow. 
This genus, iu some degree intermediate between Scomber and Gym- 
nosarda , probably contains but a single species. 
ANALYSIS OP SPECIES OP AUXIS. 
a [Body robust, scarcely compressed, abruptly contracted at caudal peduncle. Eye 
as long as snout, 5 in bear! Opercle very broad. Scales of corselet and along 
anterior dorsal region c omparatively large. Maxillary almost entirely con- 
cealed by preorbital. Dorsal spines rather stiff; the space between dorsals £ 
length of head. Gill-rakers x -J- 33. Pectorals reaching past middle of first 
dorsal. Head 4 in length ; depth, 4£. D. x-12-vin ; A. 13 -vii. Vertebrae, 
39. Blue, variegated with darker above, becoming plain with age ; belly sil- 
very.] ( Jordan Sr Gilbert ) .Thazard, 3. 
Bull. IT. S. F. 0., 87 >28 
