454 Mr. A. Alcock on the Bathyhial Fishes 



form one, followed by a small circular one, in the middle line ; 

 a large circular one behind two converging cuneiform ones in 

 each temporal region. 



Length 14 inches. 



Two specimens, females witli gravid ovaries, both in 

 fragments. 



Hah. Gulf of Manaar, lat. 6° ;]2' N., long. 79° 37' E., in 

 G75 fathoms. 



Halosaurichthys, gen. nov. 



Differing from Halosaurus in possessing a long rudimentary 

 second dorsal fin and in having the ventrals united into a 

 broad flat plate. 



Halosaurichthys carinicauda, sp. nov. 



B. 13. D. 11. P. 15. V. 10. L. tr. 'i 



Head short, its length being 7^ in the total and tapering 

 from the broad branchial region to the pointed snout. Body 

 long, low, and somewhat compressed, its greatest height being 

 equal to the length of the postocular portion of the head. 

 Tail long and tapering. Snout overhanging the mouth, its 

 length three times that of the eye or of its preoral portion. 

 Preoperculura small ; suboperculura much larger than the 

 operculum. Two parallel, wide, mucous channels, closed 

 over by a thin, tough, white membrane, extend, one from the 

 preorbital to the front limit of the operculum, the other from 

 the mandibular symphysis to the hinder edge of the sub- 

 operculum. Eyes lateral, small, their major diameter 3| in 

 the postocular portion of the head and greater than the width 

 of the interorbital space. Nostrils large, the anterior sepa- 

 rated from the posterior by a broad, black, outstanding loop 

 of skin. Mouth narrow ; the maxilla not reaching to the 

 vertical from the front margin of the orbit. Villiform teeth 

 in bj'oad bands in the jaws and hyoid, forming a broad crescent 

 ill the prominent loose palatines and a short narrow band in 

 the pterygoids. Gill-membranes entirely separate ; four 

 gills ; first branchial arch with some rather long bacillate 

 gill-rakers. Head covered everywhere, including the glosso- 

 hyal region, with small or minute adherent scales. Body with 

 large, thin, rather deciduous, cycloid scales, not larger along 

 the lateral line than elsewhere. Small scales on the lower 

 half of the dorsal fin and along the extreme base of the anal. 

 The lateral line shows as an indistinct opaque white thread. 

 Dorsal fin short, arising just behind the origin of the ventrals. 



