THE SHORE FISHES OF PERU 361 



Body very compressed, anterior half of body fairly uniform in 

 depth, tapering into a filamentous tail, its width nowhere greater than 

 about a third of its depth ; head large, compressed ; snout long, pointed, 

 2.7 to 3.1 in head; eye 5.3 to 6.0; interorbital 7.5 to 7.8; mouth large; 

 lower jaw strongly projecting, maxillary slipping under preorbital, 

 extending about to anterior margin of pupil, 2.55 to 2.7 in head; teeth 

 in jaws large, unequal, compressed, largest in anterior part of upper 

 jaw, these received in pits in lower jaw, with a barb posteriorly near 

 tip, palatines with a very narrow band of villiform teeth, none on 

 vomer; gill rakers short, slender, uneven, 9 to 13 more or less de- 

 veloped on lower and 7 or 8 on upper limb of first arch; lateral line 

 curved downward anteriorly, becoming straight near tip of pectoral, 

 running low on side; dorsal fin beginning a very short distance behind 

 eye and occupying nearly the full length of back, becoming very low 

 posteriorly, the rays becoming mere points within a narrow membrane, 

 longest rays near middle of fin, fully as long as snout; distance from 

 tip of snout to origin of dorsal 1.35 to 1.5 in head; anal composed of 

 short detached spines, the anterior ones directed backward, the pos- 

 terior ones forward, and some of the intermediate ones with both an 

 anterior and a posterior point; pectoral small, 2.6 to 3.2 in head. 



Body uniform bright silvery; top of head and tip of lower jaw 

 brownish; dorsal fin pale, with a dusky margin; pectoral pale at base, 

 distally dusky. 



The Mission secured four specimens, three respectively 365, 435, 

 and 440 mm. long, and the fourth and largest one with part of the tail 

 missing, all from the Gulf of Guayaquil, off Puerto Pizarro. This 

 species is very close to T. Upturns of the Atlantic, apparently differing 

 only in having a smaller average number of dorsal rays, a somewhat 

 shorter maxillary, and a slightly larger eye in proportion to length of 

 snout. That the dentition is weaker in Pacific specimens, as stated 

 by Hubbs and Hubbs (1941, p. 30), is not evident from specimens 

 compared by me. 



Range. — Southern California to northern Peru. Previously known 

 from Peru only from the ty^pe from off Trujillo. 



Family SCOMBRIDAE ": Mackerels 



Body rather elongate, not much compressed, usually fully stream- 

 lined; caudal peduncle slender, often depressed, and with a lateral 

 keel; head moderate, pointed; mouth large; premaxdlaries not pro- 



" This family was divided by Kishinouye (1923) into four groups, or families, namely, Scombridae, 

 Cybiidae, Thunnidae, and Katsuwonidae, the classification being based largely on internal characters 

 (anatomy). As difBcult dissections are involved, and as some of the characters are scarcely usable except 

 by an expert, I am following the old classification, that is, reuniting all the groups under one family. This 

 seems especially desirable inasmuch as the present paper is expected to be usable by some who are not 

 specialists. If the student wishes to follow the classification cited, he is referred to the paper by Kishinouye, 

 or he may turn to a paper by Jordan and Hubbs (1925), which also contains Kishinouye's classification, 

 and to Jordan, Evermann, and Clark (1930, pp. 256, 257) who took the genus /Icant/ioci/bium away from the 

 Cybiidae, as understood by Kishinouye, and set up the family Acanthocybiidae for it. 



