34 



" very wide, gill-laminae very short. Preoperculum armed with a flat spine. 

 "Abdomen protected by dermal scutes which form a serrated edge. One 

 " dorsal fin the anterior rays of which are spinous. Ventrals with six soft rays : 

 "pectoral symmetrical. Caudal deeply forked. Air-bladder simple. Pyloric 

 "appendages numerous." Giinther. 



18. Hoplostethus mediterraneum, Cuv. & Val. 



Hvplostethus mediterraneum, Cuv. & Val. Giinther, Challenger Deep-Sea Fishes, p. 21 (ubi synon.). 



See also Vaillant, Exp. Sci. Travailleur et Talisman, Poiss., p. 378 : Giinther, Ann. Mag. Nat. Hist. IV. 1889, 

 p. 417: CaruB, Prodr. Faun. Medit II. p. 616: Alcock, Jonrn. As. Soc. Bengal, Vol. LXIII. 1894, pt. 2, p. 116 : 

 Goode and Bean, Oceanic Ichthyology, p. 189, fig. 208 : Jordan and Evermann, Fishes of North America, I. p. 

 837 : K. Koehler, Campagne du Caudan, Poissons, p. 484. 



Illustrations of the Zoology of the Investigator, Fishes, pl. XIV. fig. 3. 



B. 8. D. VI. 13. A. III. 9. P. 18. V. I. 6. L. lat. 28-29. 



Height of body rather over 2\, length of head 2 1 - in total without caudal. 



As in Monocentris the head cheeks and preopercles are occupied by large 

 deep square and rhomboidal muciferous cavities, which, however, are covered by 

 a thin skin. A strong flat supra-clavicular spine, and a much stronger one at 

 the angle of the preopercle. 



Snout not overhanging the mouth, its length (including the prominent tip 

 of the mandibular symphysis) is somewhat less than the diameter of the large 

 round eye : the latter is about 3^ to 3^ in the length of the head and a little 

 less than the width of the convex inter-orbital space. Nostrils large, situated 

 near the upper angle of the orbit. 



Mouth-cleft wide, very oblique (nearer the vertical than the horizontal) ; 

 the lower jaw, though closing within the upper, distinctly prominent ; the upper 

 jaw nearly two-thirds the length of the head. Villiform teeth in the jaws, and 

 in a short and narrow band in the palatines. 



Gill-cleft wide : some gill-rakers on the outer side of the first arch are more 

 than three-fourths the length of the eye : large pseudobranchia?. Opercle striated. 



Body covered with scales of uneven size, those of the lateral line, to the 

 number of 28 or 29, being enlarged. On the back and tail, and on the throat 

 and near the middle line of the belly, the scales are sharply granular, but behind 

 the gill-opening and on the sides of the belly they are smooth. In the middle 

 line of the belly the scales, to the number of 11 to 13, are enlarged and strongly 

 keeled — the keels ending very acutely. 



Pectorals large, reaching more than half-way along the anal. Ventrals 

 reaching two-thirds of the way to the vent. 



Colours in spirit, warm brown or plum-colour with a silvery sheen. 



