20 BULLETIN 18 0, UNITED STATES NATIONAL MUSEUM 



Family ECHIDNIDAE 



KEY TO THE GENERA OF ECHIDNIDAE REPRESENTED BY SPECIMENS IN THE 

 NATIONAL MUSEUM FROM THE PHOENIX AND SAMOAN ISLANDS 



la. Some of teeth molarlike or granular, usually and at least on vomer; body 

 somewhat compressed ; eye small ; posterior nostrils on upper surface of 



head above or before ej^e Echidna Forster 



1&. None of teeth molarlike, even on vomer, although they may be short and 

 conical ; anus near middle of length, so that head and trunk are contained 

 less than 1^4 times in tail. 

 2a. Dorsal and anal fin reduced to rudiments near caudal fin, with which they 

 are confluent ; eye small ; body rounded or compressed. 



Uropterygius Riippell 

 2b. Median fins not reduced to rudiments, dorsal beginning before gill openings 

 and anal fin just behind anus. 

 3a. Posterior nostrils in a tube longer than tube of anterior nostril. 



Murenophis Cuvier 



36, Posterior nostrils not a long tube as in Murenophis. 



4a.. Anterior nostril tubular near end of snout, with a thickened bilobed 



projection or flap on posterior distal margin of low tube ; posterior 



nostril larger than pupil, with a raised rim, located in front of upper 



margin of eye Enchelynassa Kaup 



4b. Anterior nostril a simple tube without cirri or developed lobes at its tip ; 

 posterior nostril near front of eye and about same size as pupil or 

 smaller Gymnothorax Bloch 



Genus ECHIDNA Forster 



Echidna Forster, Icones ineditae, p. 181, 1777. (Type, Echidna varicgata Forster. ) 



KEY TO THE SPECIES OF ECHIDNA FROM THE PHOENIX AND SAMOAN ISLANDS 



la. Tail (anus to tip of tail) about 2 times in head and trunk (tip of snout to 

 anus) ; toothed part of vomer pear-shaped, in 6 or 8 or more irregular rows 

 of teeth; dentary with several rows of teeth; body blackish or brownish, 

 with more than 40 white rings. For proportional measurements see 



table 2 Echidna zebra (Shaw) 



lb. Tail about equal to or a little longer than head and trunk. 

 2(1. About 24 to 30 white rings on a blackish to brownish background of color, 

 sometimes rings are apparent only posteriorly on large specimens ; toothed 

 part of vomer somewhat oblong (more or less pear-shaped on large speci- 

 mens) with 4 to 6 irregular rows of teeth ; dentary with a large inner row 

 of teeth, and with an outer row of smaller teeth of equal length to the 



inner row Echidna polyzona (Richardson) 



2h. No white rings around body; vomerine teeth in one or two rows (possibly 



tliree rows in very large specimens). 



3a. Two lengthwise rows of 25 or 30 black starlike blotches with pale centers, 



the blotches more or less connected with reticulated black lines or fine 



black spots ; in young these black spots have regular edges and lack the 



white centers ; two rows of teeth on vomer, except last two teeth are 



in midline; one row of teeth on maxillary Echidna nebulosa (Ahl) 



3&. No starlike blotches or black spots on side of body. 



4a. Color brownish, with very fine reticulated pale lines in form of an 

 irregular network ; dorsal and anal fins as well as snout of same 

 color as rest of body; two rows of te(>th at head of vomer becoming 



