382 Mr. C. T. Regan on the Osteology and 



snout ; teeth cardiform, in bands ; nostrils latei'al ; gill- 

 openings well separated ; pharyngeal apertures of branchial 

 clefts restricted ; pharyngeals ovate or oblong, covered with 

 small teeth. Frontals paired ; suspensorium vertical ; palato- 

 pterygoid very slender, not laminar. 4 pectoral radials. 

 Neural spines long and slender ; caudal vertebrae without 

 transverse processes. 



Myroconger compressus, from St. Helena, appears to be 

 quite as closely related to the Anguillidse as to the Murtenidse. 



Family 6. Murapnidae. 



Naked, compressed or cylindrical ; vertical fins variously 

 developed; no pectorals. Mouth terminal, with lateral cleft 

 extending behind eye; maxillary articulated with ethrao- 

 vomer at some distance from end of snout; teeth strong, 

 acute or obtuse, in one or more series; nostrils lateral ; gill- 

 openings well-separated; pharyngeal apertures of branchial 

 clefts restricted ; upper and lower pharyngeals bearing 

 strong curved teeth in a double series, elongate, supported 

 by the enlarged epi- and ceratobranchials of the fourth arch. 

 Frontals pail red ;- hyomandibular with broad head; palato- 

 pterygoid very slender^ almost vestigial. Neural spines 

 developed in caudal region only, short, laminar; caudal 

 vertebise with lateral transverse processes. 



Alurcena^ Oymnothorax, Echidna, Strophiodon, Thyrsoidea^ 

 lihinomurcena, Murcenohlenna, Channomu7'ce?ia, Enchelychore, 

 &c., from tropical and temperate seas. 



Family 7. Heterenchelidae. 



Kaked, cylindrical, with the tail much longer than the 

 trunk ; vertical fins well developed only towards the end of 

 the tail ; pectorals absent. Mouth moderate, with lateral 

 cleft extending behind the very small eye ; maxillary articu- 

 lating jvith ethmoid near end of snout ; teeth conical, biserial ; 

 nostrils lateral ; gill-openings separate; pharyngeal apertures 

 of branchial clefts wide ; pharyngeals oblong or ovate, 

 covered with small teeth. Heart just behind the gills. 

 Frontals paired, anteriorly with strongly developed mucous 

 channels ; vomer distinct, united by suture with ethmoid ; 

 orbitosphenoids long and narrow, separating parasphenoid 

 from frontals ; prootic and basioccipital swollen to form a 

 thin-walled bulla containing a large otolith. Suspensorium 

 vertical ; palato-pterygoid a rather broad lamina. Neural 



