232 OSTEOLOGY OF MUR.3<:NES0CID^ GILL. 



Description. 



Body tyinciiUy auguilliform, with the caudal portiou or tail moderately 

 attenuated backwards, aud with the auus in the anterior half of the 

 length. 



Scales absent. 



Lateral line distinct, nearer the back than abdomen in front, about 

 midway between the two for most of its length. 



Head compressed, elongate, attenuate forwards, with all the bones 

 invested in the skin. 



JEyes within the anterior half of the head's length, entirely lateral, 

 moderate, and covered by thin skin. 



Nostrils lateral; the posterior considerably in advance of the eye, 

 X^atulous, but with a raised border ; the anterior tubiform and nearer 

 the front of the snout than eye. 



Mouth with the cleft deep and extending beyond the eyes. 



Jaws rather slender; maxillines remote from the front of the anteal, 

 with the clasping processes feeble and appressed only to the lower por- 

 tion of the anteal in front of the j)Osterior nostrils and far behind its 

 head; each ramus has a broad horizontal ledge-like expansion behind 

 under the orbits and is correspondingly depressed from above, and 

 thence becomes compressed aud dilated into oar-like expansions, over- 

 lapping and closely appressed to the lower jaw ; mandible \v\t\i the rami 

 elongated and slender ; each deutary has a well-developed coronoid and 

 constitutes most of the ramus ; the articular is exceedingly contracted 

 and developed only as a posterior cap to the dentary round the articu- 

 lar condyle. 



Teeth well developed, especially on the front and median line of the 

 anteal; generally in three rows on the anteal and ledge of each maxil- 

 liue, aud with the teeth of the median row more or less enlarged; also 

 generally in three rows on each dentary, and with the teeth of the median 

 row enlarged. 



Lips undeveloped. 



Tongue rudimentary, not free. 



Opercular apparatus moderately developed ; operculum oblong and 

 thin; suhoperculum simulating a brauchiostegal ; interopercidum mod- 

 erate, and mostly overlapped by the preoperculum ; preoperculum well 

 developed, but excavated by muciferous pores. 



Branchiotremes iu front of or lower than the inferior rays of the pec- 

 torals, rather large, and with the membrane in front emarginated by a 

 deep sinus. 



Branchiostegals iu considerable number (about 17 to 23 pairs), extend- 

 ing along the ceratohyals and epihyals, and with the brauchiostegal 

 membrane well develoj)ed and connecting the bones of the opposite 

 sides; the rays moderately bowed. 



Dorsal, anal, and caudal continent iu one uuiuterrupted fin, with the 



