that a 41.0-niiii. metainorpliosed specimen liad an 

 adult coinplenient of 30 Hrnily fixed lateral line 

 scales makes this unlikely. 



A 30.1-mm. specimen had no ctenii on the 

 scales, but a 42.4-mm. specimen had 18 ctenii on 

 one of the scales. These ctenii appear to be set 

 into niar<rinal sockets. The ctenii had increased 

 to 52 in a r)0.2-nnn. specimen and 141 in a 189.0 

 mm. specimen. The ctenii of the scales of the 

 189.0-mm. specimen had chan<red in appearance so 

 tliat they resembled sharplj- pointed c«lls pro- 

 trudinfr from the margin of the scale, the outer- 

 most of a series of other cell-like structures, 

 rectangular in shape. 

 Barbels 



In an 18.5-mm. specimen both barbels were free 

 from the branchiostegal membrane except at the 

 tip of tlie right barbel. In a 21.6-mm. specimen, 

 neither barbel was free, but had separated at the 

 base. Both barbels were free at 29.0 mm. and 

 larger sizes. 

 Operculum 



Tlie adult has a strong opercular spine at about 

 the anterior end of the lateral midline. There was 

 no evidence of this sjiine on an 18.5-mm. specimen. 

 It was noted on a specimen of 21.6 mm., but the 

 t ip did not extend to the margin of the operculum. 

 On a 29.0-mm. specimen it was clearly seen, as it 

 was on all larger specimens examined. A second 

 small spine, anterior to the large spine, was noted 

 on an occasional large specimen. 

 Cleithruin 



The cleitJirum liad an enlarged winglike process 

 just posterior to the upper angle of the opercular 

 flap. It had a remarkable resemblance to a scale 

 as it acquired the pigmentation occurring as a dark 

 blotch in this region. At a size of approximately 

 40 mm., the same size at which the scales become 

 clenoid, this small prominent bone had serrations, 

 further increasing its similarit}' to a ctenoid scale. 

 At sizes above 50 mm. this serrated cleithral wing 

 was the quickest and easiest method of identifying 

 P. mnculatus, as this character is peculiar to this 

 si^ecies of the Mullidae of the western North 

 Atlantic. 



The upper wing of the cleitlinim of a 40.0 mm. 

 juvenile and its position relative to the operculum 

 and opercular spine are illustrated (fig. 23) . 



MULLIDAE OF THE WESTERN NORTH ATLANTIC 



I 



431 



Figure 23. — Otwreulum and 

 Pseudupenetis maciilatiix. 



cleithrum of 46.0-nim. 

 Line equals 2 mm. 



SPAWNING 



Forty-mm. specimens taken as early as January 

 1 and as late as July 25 (table 2) suggest a pro- 

 tracted sjiawning period. 



SEXUAL DIMORPHISM 



Eight large, mature P. maculatus, four 190.0- 

 to 206.0-mm. males and four 165.0- to 181.0-mm. 

 females, were examined for sexual dimorphism. 

 The males tended to have higher arched backs and 

 more angular facial profiles, whereas the females 

 tended to be more fusiform and have a sloping 

 facial profile. The angulation of the profile and 

 arched back of the male was more pronounced 

 with increase in size. 



The 197.0-mm. specimen plotted on the graphs 

 of body proportions (figs. !) through 21) is a fe- 

 male, and the 198.0-mm. specimen is a male. These 

 two spe<"imens, the most extreme of the ones 

 examined, illustrate sexual dimorphism for this 

 species. 



MULLUS AURATUS JORDAN AND GILBERT 



Pertinent station data and sources of material 

 are given in table 7, p. 429. 



