DIAGXOSES OF THE FAMILIES, GEXERA AND SPFCIFS. Ill 



stalk. Parenchymal liexactins with curved rays. The hexastcrous 

 discohexaster (46-70/^- dia.), present besides the hexactinose form 

 (100-180 /-« axial length), is spherical in shape. Of inconstant 

 occurrence is the small and delicate tylfloricome. 



CHAUNOPLECTELLA Ij. 



Leucopsacids with moderately large, ovoid or vase-like and 

 thick-walled body, attached by short stalk-like base. Parenchy- 

 malia chiefly hexactins and diactins. Dermalia either all pent- 

 actinic or with a variable number of rays, none of which however 

 are distally outstanding. Gastralia represented by hexactins 

 similar to those of the parenchyma. Discohexasters always 

 hexasterous, the lai-ger ones with terminal prongs arranged in a 

 whorl like anchor-arms ; with or without sigmatocome in addition. 



CJiaunojilectella cavernosa Ij. — Cliaunopleclella of moderate- 

 ly large size ; sometimes laterally compressed ; with wide canals 

 and subdermal sj^ace. In young and small specimens the dermalia 

 and parenchymal ia are as in Levcopsacus ; but in the larger ones 

 both consist of irregular spicules with a varying number of rays, 

 though the dermalia never show a freely outstanding distal ray. 

 Discohexasters of varying size and appearance ; when fully de- 

 veloped, they may attain a diameter of 250-100/^, and then 

 have the terminal whorl of reverted prongs shaped like a bell 

 expanding towards the rim. Small delicate sigmatocome present 

 in addition to the above. 



Çhaunoplectella sphiifera n. sp. — ÇhaunoplcdiUa of ovQid 



