2074 Bulletin 47 ^ United States National Museum. 



able ill leugth, averaging \ head. Supraocular ridges strong, rugose, 

 ending in a sliort strong spine; an inner pair of ridges occupying floor 

 of interorbital groove, very broad and closely joined anteriorly; the 

 triangular space included between these latter ridges flat and opening 

 posteriorly onto the depressed occipital area; occipital ridges low, 

 rounded, ending in very strong spines which form the first of the dorsal 

 series; 2 or 3 small rounded projections may occur on anterior ridges of 

 the occipital spines ; top and sides of head more or less closely beset 

 with very fine prickles, which are most thickly clustered on occiput, 

 interorbital area, upper part of opercles, suborbital chain, and sides of 

 snout; a row of prickles on eyeball just above pupil; temporal ridge 

 uneven, sometimes interrupted with a long, strong posterior spine; a 

 strong spine, sometimes with an accessory tubercle on middle of cheek; 

 preorbital with 2 pairs of spiues placed vertically, the upper ones di- 

 rected outward and upward, the lower spiues directed downward and 

 backward; rostral ridges rough, usually terminating posteriorly in a 

 pair of spinous projections, which are located midwaj^ between tip of 

 snout and front of pupil; anteriorly, at tip of snout, these ridges expand 

 to form such a vertically projecting rounded spinous lobe, the posterior 

 spine of which is much the strongest, and points backward and outward. 

 In the very young the last-mentioned spiues alone are present on snout, 

 and are directed very obliquely backward; anteriorly ridges converge 

 from them to tip of snout, and are very minutely serrulate; these ridges 

 afterward increase in height and in strength of serrations, and become 

 the spinous lobes already described; two strong diverging spines at 

 angle of preopercle, and 2 rounded lobes below them. Three large plates 

 and a number of smaller ones occupy cheek below suborbital stay. Pos- 

 terior portion of mandible expanded into a rough projecting bony promi- 

 nence. Mouth horizontal, overpassed by the snout in adults for a distance 

 equaling i or less than \ diameter of orbit; snout not noticeably pro- 

 jecting in the very young. Maxillary reaching slightly beyond front 

 of orbit, equaling \ length of snout and eye. Teeth in broad bands in 

 jaws; a distinct patch on front of vomer, none on jialatines. Branchios- 

 tegal membranes broadly joined, with a very narrow free fold posteriorly, 

 or with none. Six pairs of barbels on under side of head ; 1 on under side 

 of snout in front of premaxillaries; 2 at end of maxillary; 1 near mid- 

 dle of maxillary; 1 on lower lip just below angle of mouth; 1 forked for 

 \ its length at middle of side of lower lip. In their distribution, rela- 

 tive lengths, and in the constantly bifid character of the last described, 

 they correspond exactly with the barbels of L. decagonus, but the latter 

 has apparently none on under side of snout. Interspace between dorsals 

 somewhat variable, f to | diameter of orbit. Anal beginning 2 plates in 

 advance of second dorsal ; pectorals .5i in length of body, the lower rays 

 graduated, 4 to 6 of the lower ones tljickened, with exserted tips; ven- 

 tral fins nearly twice as long in males as in females, in the latter less than 

 diameter of orbit; caudal slender, 1| in head. Color light grayish or 

 brownish, pale below; a Iduish black stripe from ventral spiues to front 

 of orbit; suborbital, preopercle, and opercle with numerous dark spots; 



