BY W. MACLEAY, F.L.S. 227 



part of the mandible being the longest ; maxillary teeth in a 

 single series, those of its lower two-thirds being very small ; 

 teeth of the hinder part of the mandible in a double or treble 

 series ; vomer with a pair of fangs ; palatines with a single 

 series of small, pointed teeth ; two groups of similar teeth on the 

 tongue, Eye of moderate size. Opercular portion of the head 

 very narrow and flexible. A fleshy barbel is suspended from the 

 centre of the hyoi.l region. Dorsal fin opposite the anal, close to 

 the caudal ; caudal forked. Pectoral and veutral fins feeble, the 

 latter inserted behind the middle of the length of the body. 

 Series of phosphorescent dots run along the lower side of the 

 head, body, and tail. Gill-openings very wide ; the outer branchial 

 arch with minute gill-rakers ; pseudobranchiae none. Air-bladder 

 none. 



Atlantic and Pacific Oceans. 



838. Echiostoma microdon, Gunth. 

 Ann. and Mag. Nat. Hist., 1878, Vol. II., p. 180. 



D. 24. A 29. P. 3. V. 7. 



The length of the head is more than one-fifth of the total length 

 (without caudal). No separate pectoral ray; root of the ventral 

 considerably nearer to the base of the caudal than to the extremity 

 of the snout. All the teeth rather small, a few only in the middle 

 of the palatine bone. Black ; two luminous organs below the 

 eye ; a narrow elongate one above the maxillary, and a small, 

 short one nearer the eye. 



North-west Coast of Australia, 2,440 fathoms (Challenger). 



839. Echiostoma micripnus, Gunth. 

 Ann. and Mag. Nat. Hist., 1878, Vol. II., p. 180. 



D. 21. A. 23. P. 1/3. V. 7. 



The length of the head is nearly one-ninth of the total length. 

 Barbel much longer than the head, and fringed at its extremity ; 



