REPORT ON THE DEEP-SEA FISHES. 109 



Gill-rakers ten, much longer than the laminae. Whitish, with the abdomen and gill- 

 apparatus black. 



Habitat. — One specimen, 5^ inches long, was obtained in Mid-Atlantic (Station 104), 

 at the enormous depth of 2500 fathoms. 



Bathyonus. 



Bathynedes sp., Giinth., Ann. and Mag. Nat. Hist., 1878, vol. ii. p. 20. 

 BathyoniLs sp., Goode and Bean, Proc. U.S. Nat. Mus., voL viii., 1886, p. 603. 



Body compressed, with long tapering tail, covered with deciduous thin scales of 

 moderate size. Bones of the head very soft and cavernous, the upper opercular spine 

 very feeble, ridge-like ; no other armature on the head. Head scaly, except the snout, 

 which is obtusely rounded oft*, with the jaws equal or nearly equal in front. Mouth very 

 wide ; bands of \'illiform teeth in the jaws, on the vomer and palatine bones. Barbel 

 none. Eyes small. The anterior nostril about midway between the posterior and the 

 extremity of the snout. Vertical fins confluent ; ventrals close together, reduced to a 

 pail' of simple filaments, and inserted below the rounded angle of the prseoperculum. 



Gills four, with short gill-lamina3, but with long stifi" gill-rakers on the first branchial 

 arch. Pseudobranchiaj none. Branchiostegals eight. Pyloric appendages none. 



Bathyonus compressus (PI. XXII. fig. A). 



Bathynedes eampressus, Giintli., Ann. and ^lag. Nat. Hist., 1878, vol. ii. p. 20. 

 D. 116. A. 92. P. 23. V. 1. 



The greatest depth of the body is above the end of the gill-cover and about one-half 

 of the length of the trunk, the vent being twice as distant from the extremity of the 

 tail as from the snout; consequently, the tail is but moderately attenuated. Head 

 compressed like the body, and about two-thirds of the length of the trunk ; the 

 superficial bones form large muciferous cavities which, when full, must give to the head 

 a much more evenly rounded appearance than in the preserved state, when the supporting 

 bony ridges project more or less from under the skin. The snout is slightly swollen, but 

 the jaws are nearly even in front, the wide mouth slightly ascending forwards. The 

 maxillary has the form usual in these Gadoid fishes, is dilated behind, and extends far 

 behind the eye. 



The eye is very small, one half of the length of the snout, and about one-eleventh of 

 that of the head ; it is placed high up on the side, and does not possess an orbital 

 fold of the integument. The interorbital space rather convex and equal in width to 

 three diameters of the eye. 



