344 



A. Head and trunk i'/ 2 to more than twice in tail. 



a. Tubes of anterior nostrils with a foliaceous 

 appendage. Tip of snout and of lower jaw 



with barbel-like appendages Rhinomuracna p. 352. 



b. Anterior nostrils in a simple tube. No barbel- 

 like appendages Thyrsoidea p. 354. 



B. Head and body equal to., somewhat shorter or 

 longer than tail. 



a. Dorsal and anal reduced to rudiments near 



caudal, with which they are confluent .... Gymnomnracna p. 392. 



b. Vertical fins not reduced to rudiments : dorsal 

 beginning before gillopenings, anal imme- 

 diately behind anus Muraena p. 356. 



i. Echidna J. R. Forster. 



(J. R. FORSTER, Enchiridion hist. nat. 1788, p. 81). 



Elongate, compressed. Head compressed, its dorsal profile 

 strongly arched. Eye small, covered by skin. Anterior nostrils 

 in a tube on top of snout, posterior nostrils on upper surface 

 of head before or above eye. Cleft of mouth rather wide, 



Fig. 168. Echidna zebra (Shaw.) X 3 /5- 



reaching behind eye. Pectorals absent. Dorsal beginning before, 

 above or somewhat behind gillopenings, confluent with caudal 

 and anal. Dorsal and anal covered by thick skin. Tail equal 

 to or somewhat longer or much shorter than head and trunk. 

 Teeth conical, granular or molarlike, often changing with age 



