1941 CATALOGUE OF FISHES OF TOR1TJGAS rfj 



This species is readily recognized by the deeply notched dorsal fin, the spinous 

 and soft parts being nearly or quite separate, and by the reduced number of 

 dorsal spines, the formula being X-I,io and XI-I,io in 2 Tortugas specimens. The 

 head is cavernous, with large pores, and the preopercle has 5 prominent spines. 



In deep water from southern New England to Florida. S. F. H. 



Family PERISTEDIIDAE 



Peristedion Lacepede 



Peristedion Lacepede, Hist. nat. poiss., vol. 3, 1802, p. 368 (P. malarmat Lacepede = Trigla 



cataphracta Linnaeus). 

 Vidsictdus Jordan and Evermann, Check list, 1896, p. 489 {Peristedion imberbe Poey). 



Members of this genus are notably specialized. They are also so true to their 

 several types that multiple differences in proportions, in length, shape, and degree 

 of divergence of their rostral processes, in the arrangement of their barbels, the 

 number and form of their cephalic keels and spines, sculpturing of their scutes, 

 and form and proportions of the terminal spines of the three series ending on 

 either side of the caudal fin readily distinguish them. W. H. L. 



The following key will aid in showing the relations of the local species. 



S. F. H. 



Key to the Species 

 a. Rostral processes very long and thin, much longer than eye, about 

 2.6 to 3.0 in head (head measured from base of rostral processes 

 to tip of opercular spine); head quite to moderately narrow, its 

 width about 1.7 to 2.7 in its length 



b. Head very narrow, preopercular ridge scarcely expanded, its 

 width about 2.5 to 2.8 in its length; last scute (on base of 

 caudal) in lateral-line series very small, much smaller than those 

 in dorsal and ventral series; principal mandibular barbel short, 

 about reaching angle of mouth; lower part of side with a silvery 



band imberbe 



bb. Head broader, the preopercular ridge much more prominently 

 expanded; last scute in lateral line not much if any smaller than 

 those in dorsal and ventral series; mandibular barbel longer, 

 reaching nearly to base of ventral; no silvery band on side . longispathum 

 aa. Rostral processes notably shorter and thicker, equal to or shorter 

 than eye, about 4.4 to 8.0 in head; head very broad, expanded pos- 

 teriorly, its width about 1.4 to 1.5 in its length 



c. Spines on head very strong; supraorbital ridge with 3 prin- 

 cipal spines and some smaller ones; rostral processes very short, 

 about 8.5 to 9.5 in head; principal mandibular barbel very 



long and thick, reaching base of pectoral miniatum 



cc. Spines on head notably smaller; supraorbital ridge with only 



1 small spine, placed over posterior part of eye; rostral processes 



somewhat longer, about 4.2 to 5.5 in head; principal mandibular 



barbel shorter and much more slender 



d. Spines on scutes in arch of lateral line obsolete; eye large, 



