168 PAPERS FROM TORTUGAS LABORATORY vol. xxxiv 



its diameter greater than interorbital space, about 3.5 to 3.8 

 in head; principal mandibular barbel scarcely reaching 

 angle of mouth; lower part of side with a silvery band . platycephalum 

 dd. Scutes in arch of lateral line with definite spines; eye 

 notably smaller, its diameter about equal to interorbital, 

 4.1 to 4.6 in head; principal mandibular barbel longer, 

 reaching nearly to opercular border if laid straight back; 

 no silvery band on side spiniger 



Peristedion imberbe Poey 



Pterystedion imberbe Poey, Memorias, vol. 2, 1861, p. 367 — Cuba. 



Peristedion micronemns Poey, Ann. Lye. Nat. Hist. New York, vol. 9, 1870, p. 321 — Cuba. 

 Peristedion gracile Goode and Bean, Ocean. Ichthyol., 1895, P- 473> hg- 387 — Gulf of 

 Mexico. 



A rather common fish, taken between 40 and 94 fathoms; reaching at least 

 175 mm. in length. 



Head little depressed, very slightly expanded posteriorly; rostral processes 

 thin, nearly parallel, almost half as long as distance from their base to pre- 

 opercular margin; spines of head in adult very weak or wholly absent; preorbital, 

 nuchal, and preopercular spines relatively stronger in young; spines on scutes in 

 arch of lateral line weak or wanting; median lateral scute at base of caudal with 

 a weak nonserrate spine or none; other 2 scutes each with a strong spine, strongly 

 serrate on its outer margin; 2 anterolateral fringed barbels beneath lower jaw, 

 reaching slightly beyond angle of mouth; a pair of short barbels, and a group of 



3 before these on anterior margin of jaw; other barbels half their length behind 

 them and beneath the jaw. 



That the type of Peristedion imberbe, which I examined in the Museum of 

 Comparative Zoology, is the young of P. gracile is indicated clearly, despite its 

 small size (total length 55 mm.) and mutilation, by its compressed head, reticu- 

 late pattern of dark lines on pectoral fins, and the weak, unserrated spine of last 

 scute of lateral series ending at base of caudal. W. H. L. 



The collection contains a fine series of specimens. The following proportions 

 and enumerations are based on 3 individuals, respectively 100, 145, and 148 mm. 

 long: Head in standard length (both measured without rostral processes) 2.5 to 

 2.6; depth 5.9 to 6.1; anal base 2.3 to 2.4. Eye in head (measured between bases 

 of rostral processes and tip of opercular spine) 2.0 to 2.1; eye 5.5 to 5.8; inter- 

 orbital 4.8 to 5.1 ; width of head 2.5 to 2.8; rostral process 2.6 to 2.8; ventral 2.0 to 

 2.1; pectoral 2.0 to 2.3. D. VIII,2o; A. 18 or 19; P. 12 + 2; scutes in lateral line 



4 + 29 or 30 + 0; gill rakers 18 or 19. 



Preserved specimens are plain, with a bright silvery band between median 

 lateral (lateral-line) row of scutes and ventral ones, which among local species is 

 present only in this species and P. platycephalum. The pectoral is largely white 

 with dusky areas. The first dorsal, too, is largely white, with a dusky band on 

 mid-length of rays; second dorsal with pale spots and a dusky band. 



Gulf of Mexico to West Indies. S. F. H. 



