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NEW GENERA AND SPECIES OF ECHINODERMATA, 



liY S. A. MILLEH AND \VM. F. E. OUKEEV. 



SUBKINGDOM ECHINODERMATA. 



CLASS CRINOIDEA. 



ORDER CYSTOIDEA. 



FAMILY HOLOCYSTID.E. 



H0L0CYSTITE8 GYRINUS, 11. Sp. 



Plate I, Fi(j. J, vfiilrdl rieic: Fig. V, postcn'or ririr : Fig. :i, 



,^inumil I'irir. 



This species is large, aud if tlie aliii(i.st perfect specimeu, wliicli 

 we have illustrated, possesses tlie normal form of complete de- 

 velopment, then it became free iu the later stages of growth, for 

 a scar at the terminal point, indicates an attachment to some 

 foreign object in a younger state. Tiie specimen is a little de- 

 pressed dorso-ventrally. It is broad aud rounded at the summit, 

 followed immediately below by a sac-like swelling, from which it 

 is continued in an obconoidal form until it terminates iu an ob- 

 tuse point. The fanciful resemblance, iu the general outline, to a 

 tadpole suggested the specific name. 



Commencing at the base or lower end, tliere is a solid obconoidal 

 piece nearly as long as its greater diameter, which is followed by 

 a range of eight unequal, irregular, and more or less elongated 

 plates. Two filates are inserted between this range and the nest on 

 the right part of the ventral side. There are eleven large and elon- 

 gated plates in the second range, and three plates are inserted on 

 the posterior side, between it and the next range. There are thirteen 

 large, irregular and elongated plates in the third range and nine- 

 teen plates in the fourth range. The fifth range consists of plates 

 more irregular in their order of arrangement aud still more 



