436 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



between ■which they are intercalated. Medial part of branchiostcgal meiiiljrane and 

 the gnlar region covered Avith roundish i)late8, the whole forming a halbert-shaped 

 patch. Lateral line running on a series of small i)lates occujiying the middle of the 

 lateral face. Anteriorly these entirely disappear, the lateral line ascending and 

 running on the upper lateral series. About five largo plates, sometimes bearing 

 spines, lie behind upper axil of pectorals, between this ascending portion of the 

 lateral line and the inferior lateral series of plates. 



Head depressed, tapering rapidly to the snout; depth of head at occiput two- 

 thirds its width at jireopercular spine, the latter contained 6J^ times in length of 

 body. Eye large, the orbit about eiiualing length of snout behind the serrated 

 rostral ridge, 3i to 3j in head. Snout somewhat variable in length, averaging one- 

 third head. Supraocular ridges strong, rvigose, ending in a short, strong spine. An 

 inner i)air of ridges occupies the floor of the iuterorbital groove, very broad and 

 closely joined anteriorly. The triangular space included between these latter ridges 

 is flat and opens posteriorly onto the depressed occipital area. Occipital ridges low, 

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

 or three small, rounded projections may occur on anterior ridges of occipital spines. 

 The top and sides of head are more or less closely beset with very fine prickles, 

 which are most thickly clustered on occijiut, iuterorbital area, upper part of opercles, 

 suborbital chain, and sides of snout. A row of jirickles on eyeball, just above pux)il. 



Temporal ridge uneven, sometimes interrupted witli a long, strong posterior spine. 

 A strong spine, sometimes with an accessory tubercle, on middle of cheeks. Pre- 

 orbital witb two pairs of spines placed vertically, the upper ones directed outward 

 and upward, the lower spines directed downward and backward. Rostral ridges 

 rough, usually terminating posteriorly in a pair of spinous projections, which are 

 located midway 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 spines alone are present on snout, and are 

 directed A-'ery obliquely backward. Anteriorly ridges converge from them to tij) 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 two rounded lobes below 

 them. Three large plates and a number of smaller ones occupy cheeks below sub- 

 orbital stay. Posterior portion of mandible expanded into a rough, projecting, bony 

 prominence. 



Mouth horizontal, over2:)assed by the snout in adults for a distance equaling half 

 or less than half diameter of orbit; the snout not noticeably projecting in the very 

 young. Maxillary reaching slightly beyond front of orbit, equaling half length of 

 snout and eye. Teeth in broad bauds in jaws; a distinct patch on front of vomer; 

 none on palatines. Branchiostcgal membranes broadly joined with a very narrow 

 free fold posteriorly or with none. 



Six pairs of barbels on under side of head : One on under side of snout in front of 

 premaxillaries ; two at end of maxillary ; one near middle of maxillary ; one on lower 

 lip just below angle of mouth; one forked for half its length, at middle of side of 

 lower lip. In their distribution, relative lengths, and in the constantly biiid char- 

 acter 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, three-fourths to seven-eighths 

 diameter of orbit. The anal begins two plates in advance of second dorsal. Pec- 

 torals 5i in length of body, the lower rays graduated, four to six of the lower ones 

 thi(;kened, with exserted tips. Ventral fins nearly twice as long in males as in 

 females, in the latter less than diameter of orbit. Caudal slender. If in head. 

 Head 4^ to 4^ in length. Dorsal vi to viii-7 or 8; anal 6 or 7; pectoral 15; ventral 

 I, 2; caudal with 11 rays and a rudiment of a twelfth below. Lateral line 40. 



