100 THE VOYAGE OF H.M.S. CHALLENGER. 



Barathrodemus ma na tin us. 



Barathrodemtis nianatinus, Goode and Bean, loc. cit. 



B. 8. D. 106. A. 86. C. 9. P. 18-20. Y. ]■. L. transv. ca. 34 (above vent). 

 Habitat. — Two specimens, 6^ inches long, were obtained by the U.S. steamer "Blake," 



in 



lat. 33° 35' N., long. 76° 0' W., at a depth of 647 fathoms. 



Neohythites. 

 Neohythites, Goode and Bean, Proc. U.S. Nat. Mus., vol. viii., 1886, p. 600. 



Body elongate, compressed, covered with small scales ; lateral line indistinct. Head 

 not compressed, covered with scales. Eye of moderate size. Vertical fins united ; 

 ventrals each reduced to a bifid filament, inserted behind the humeral sj^mphysis, and 

 somewhat distant from each other. Snout overlapping the mouth, without barbels. 

 Bands of vUliform teeth in the jaws, on the vomer and palatine bones. Operculum with 

 a long spine. Eight branchiostegals ; air-bladder present ; pseudobranchise small. 

 Pyloric appendages to 20. 



This genus has been distinguished by me for some time, but the manuscript name 

 which I proposed for it, Tetranematopus, was unfortunately introduced by me into the 

 literature without diagnosis, so that it has to give way to Neohythites. I failed to 

 recognise the latter, as it was characterised by single-rayed ventral fins, until Mr. Goode, 

 on inquiry, kindly informed me that the genus to which he had given this name has bifid 

 ventral rays, as, indeed, he had stated in the description of the species. 



Neohythites grandis (PI. XXI. fig. A). 



Sirembo grandis, Giinth., Ann. and Mag. Nat. Hist., 1877, vol. xx. p. 437. 



Head rather short and broad, with obtuse snout overlapping the lower jaw. Eye 

 small, about one-third of the length of the snout and one-eleventh of that of the head. 

 Mouth rather wide, the maxillary extending to behind the eye ; barbels none. Teeth 

 of the jaws, vomer, and palatine bones in villiform bands. The vomerine teeth form 

 a triangular patch, much broader than long ; the width of the palatine band exceeds 

 that of the intermaxillary. A deep groove in the skin descends from the anterior 

 nostril towards the maxillary, and rcasceuds towards the median fine of the extremity 

 of the snout, cutting ofi" an anterior lobe, as in some Scisenoids. Several pores, leading 

 into the muciferous system, are hidden in the groove ; a few small open pores near the 

 symphysis of the mandible. Nostrils gaping, oval openings, of which the anterior is 

 surrounded by a membranous wall. Praioperculum crescent-shaped, without any 



