Erroneous Echinodermal Identification. 107 



difference in size between " primary " and " secondary " is 

 scarcely recognizable. 



In others from Cromarty, Preservation Inlet, N.Z., which 

 are white, though the size is about the same as the type 

 (46x35 mm.), the number of tubercles is less; for in the inter- 

 ambulacrum only five tubercles occur in a transverse row, at 

 the ambitus, and this soon becomes three above and below ; 

 while on the ambulacrals two occur at ambitus, but only one 

 over the greater part of test. 



This species is readily distinguished from P. alhocinctus 

 by the small size and transverse arrangement of the many 

 tubercles on the interambulacral plates, as well as by the 

 colour of the test. 



Pseudechinus albocinctus, Hutton. 

 I do not know whether P. albocinctus has been described 

 in detail by Mortensen. But my specimens, some o£ which 

 were labelled by Hutton (as E. magellanicus), agree in general 

 with the above, but the tubercles are larger and fewer ; the 

 colour of shell purple; the primary more conspicuous than 



Fscudechimis albocinctus. 



Fig. 3. — Portions of ambulacrum aud interambiilacrumattlio ambitus (A) 



and immediately above it. X 2. 

 Fig. 4. — An ambulacral and an interambulacral plate, x -J. 



in P. huttoni. The railiaries are larger and more numerous, 

 while in the ambulacrum there are only two tubercles at 

 ambitus, e^c. 



