DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 407 



HYMENOCEPHAXUS GOODEI, (Gunther), Bean. (Figure 340.) 



Maerurus asper, Goode and Bean, Bull. Mus. Comji. Zoiil., x, 1883, 196-7 (uame preoccupied). — Jordan, Cat. 



Fish. N. Amer., 1885, 131. 

 Maerurus Goodii, Gunther, Challenger Report, xxii, 1887, 136. 

 Hymenocephalus Goodei, Bean, MS. 



The relations of this species appear to be with M. Boirdii, from which it differs in (1) 

 its longer snout, (2) tlie location of the vent, whicli is much farther bacli, and (3) the absence 

 of keels upon any of its scales. 



The length of the specimen described is 322 millimeters. The body is much stouter 

 than in M. Bairdii, its greatest height being contained Ci times in its length. The scales 

 are small, strong, the free portions covered by series of small vitreous sjiines arranged in 

 about six rows; there is no specialization of the central row, as in M. Bairdii, though the 

 median spine at the margin of the scale projects most strongly and is longest, consisting of 

 7 or 8 spines. The number of scales in the lateral line is about the same, there being about 

 150; there are 7 above and 18 below the line. 



Length of head contained 5| times in total length. Width of interorbital area a little 

 greater than horizontal diameter of orbit and length of operculum, and contained 4^ times 

 in the length of the head. Length of snout about equal to width of interorbital space and 

 about one-half the postorbital portion of the head. Snout triangular, depressed, its tip in 

 the axis of the body, and nearly on a level with the lower margin of the eye; its lower sur- 

 face forming an angle with the body axis, about equal to that formed with same by its 

 upper profile. The supei-ior ridge is pronounced anteriorly, but ends in advance of the con- 

 cavity in the interorbital space. Tlie lateral ridges are prominent, and continue posteriorly 

 to the eye, with stron g angular projections in front of the nostrils. No ridges continued from 

 supraorbital region. ISTostrils rather close to the eye. Barbel shorter than the eye. Tip 

 of lower jaw under anterior nostril ; cleft of mouth under posterior margin of orbit. The 

 under surface of the head is naked, with the exception of a few minute, spiny tubercles on 

 the under surface of the mandible. The suborbital ridge is very slightly developed. The 

 intermaxillary is a long bone, nearly as long as the maxillary, and the mouth is large. The 

 teeth on the intermaxillary are in a double series, of which the outer contains much larger 

 teeth than the inner. The teeth in the mandible are uniserial ; the dorsal spine is strongly 

 serrated. 



Distance of first dorsal from snout equal to nearly 4 times the length of its base, its 

 distance from the anterior margin of the orbit equal to the length of the head. First spine 

 minute; second spine strongly serrated as in M. Bairdii, nearly two-thirds the length of 

 the head, and when laid down is f^ir from reaching to the origia of the second dorsal. 

 When the fin is erect, its superior margin is nearly at right angles to the plane of the back, 

 and slightly convex. The distance between the two dorsals is twice the length of the base 

 of the first, the second beginning in the perpendicular from the fifth ray of the anal. 



The anal is about 3 times as higli as the secojul dorsal. The vent is under the thirtieth 

 scale of the lateral line directly in advance of the anal, and at a distance from the ventral 

 considerably greater than the length of that fin, in this respect diflering widely from M. 

 Bairdii. 



Distance of pectoral from snout slightly more than the length of the head. Its length 

 is less than that of the dorsal spine, and slightly more than half its distance from the snout. 

 Its insertion (upper axil) is in the middle line of the body. 



Insertion of ventral under that of pectoral, and slightly in advance of that of dorsal. 

 Its first ray is not greatly prolonged, and is about half as long as the distance of the fin 

 from the snout. 



The branchiostegal membrane is narrowly attached to the isthnuis, leaving no free 

 margin behind. The gill-rakers are very small tubercles, and there are only ten below the 

 angle on the first arch. 



Eadial formula: 1st D. il, S-9; 2nd D. 105; A. 110; P. 20; V. 10; scales 7/150/18. 



Color dark reddisli brown, the spines upon the scales with a metallic luster. The young 

 have 3 stellate bosses ui)on the snout, one at its tij), one at some distance upon each side. 



