530 ORDER MALACOPTERYG1I APODES. 



Synbranchus, BL, Unibranchaperturi, Lactp., 



Are distinguished at once from the sphagebranchi by 

 their branchiae communicating externally only by a 

 single hole pierced under the throat, round or longi- 

 tudinal, and common to both sides. They have no 

 pectoral fins, and their verticals are almost entirely 

 adipose. Their head is thick, muzzle rounded, their 

 teeth obtuse, their opercula partly cartilaginous ; the 

 rays of their gills are strong, and six in number ; their 

 intestinal canal is altogether straight, and the stomach 

 is only distinguished from it by a little more ampli- 

 tude and a valve to the pylorus. They are without 

 cceca, and have a long and narrow air-bladder. Their 

 habitat is in the seas of warm climates, and some of 

 them arrive to a tolerable size 2 . 



Alabes, Cuv., 



Have, like the synbranchi, a common aperture under 

 the throat for their gills, but they have well-marked 

 pectorals, between which is a small concave disk. 

 Through the skin are distinguishable a small opercu- 

 lum and three rays; the teeth are pointed, and the 

 intestines as in synbranchus. 



But one small species is known, from the Indian 

 Ocean. 



It is at the end of this great genus, Mur^ena, that 



2 Synb. marmoraius, Bl. 418. ; Synb. immaculalus, Id. 419., 

 Unlb. Cachia, Ruch. xvi. 4., Dondno-paum, Russel xxxv., has no 



fin whatever. 



