50 



SVEN LOVEN, ECHINOLOGICA. 



Discoidea is perfect, and still, at the first siglit, there seems 

 to be a great discrepancy. In the elevated form of the Dis- 

 coidea the entire system, though not as erect as iu the other 

 Regularia, is largely free and projecting, in the lower form 

 it adheres to the tumid interradials to a greater extent, but 



Galerites Albogalerus Leske. The peristome from the inside. 



Section throngh the interradium and the auricle. 



still projects not a little above it with its marginal part. In 

 the Galerites this lowering of the anricles is carried to the 

 extreme. All aronnd the peristome the whole system reclines 

 npon the test, to wliich it is soldered in its whole length, and 

 its upper margin is made distinct only by a slight impression. 



