COMPARATIFE STUDY OF SCOMBROID FISHES. 
413 
A large species of distomum, about 8 cm in length, is almost always found 
in the stomach. 
Genus Grammatorcynus Gill. 
'Grammatorcynns, Gill, 1812; Klunzinger, 1884. 
Nesogrammus, Evermann & Seale, 1807. 
Body elongated, compressed, and covered with small scales. Corselet 
indistinct. Mouth rather small, maxillary not reaching the middle of the eye. 
A deep groove in the skin from the corner of the mouth, as in many other 
forms of the mackerel-like fishes. Tongue broad. Teeth elongated, trenchant. 
Villous teeth on the vomer and palatines. Two dorsals continuous. Second 
dorsal and anal are divided into finlets in the hind part, and are lower than 
the first dorsal. Gill-rakers short and strong. Opercle with a shallow notch 
at the posterior margin. The lateral keel of the caudal peduncle is low and 
small, covered with a row of pored scales. Two lateral lines on each side of 
the body. 
Fish of this genus are also an aberrant form of the Oybiidae. The in¬ 
significant keel on the caudal peduncle, the rather small number of vertebrae, 
indistinct corselet, slightly notched opercle, backward origin of the first dorsal 
etc. connect this genus more or less with the Scombridae ; but trenchant teeth, 
continuous dorsals, large broad tongue, renal portal veins, short strong gill- 
rakers, descending pylorus, dendritic tubes to which pyloric coeca open, bent second 
basibranchial, etc. indicate that this genus is much closer to the other genera 
of the Oybiidae. 
Only one species is known from the tropical seas and adjacent waters of 
the Indo-Pacific region. 
Grammatorcynus bilineatus (Büppel). 
Kusarah. 
Figs 8, (32. 
Thynnus b lineatus, Rappel, X. W. Fische, 33, Tuf. 12, Fig. 2, 1840 ; Günther, Gat. II, 
366, 186 U 
Grammatorcynus bilineatus. Gill, Proc. Ac. Philad. 125 1862. Klunzinger, Fisch. Roth Meer, 
113, 1881 ; Kishinonye, Sui. Gak. Ho, I, 86. 1915. 
Xesoqrammus piersoni, Evermanu & Seale, Bull. Bur. Fish. XXVI, 61, 1907. 
D. 12, 9, 7. A. 10, 7. Gill-rakers 5 + 16. Vert. 13 + 18. 
