1893.] MICROSCOPICAL JOURNAL. 227 



Spines united l»y ring. Satumalis. 



R. — TWO SIMIKUKS. 



SjiincH ecjuul. SlyloHpluera . 



Spines different. Sphaerodyhis. 



3.— Fiimily: STAUROSPH.FJJI DA. F..ur radial spines 

 Ibruiing a cross. 



A. — ONK Sl'HKUK. 



All fonr spines ecpial. Stauroftjihitra. 



H. — TWO Sl'HKRES. 



All four s{)ines equal. Staurolonche. 



Four s|)ines diflerent in ))airs. Staurolonrhidiiim. 



('. — THREE SPHERES. 



All four spines equal. Stauracontium. 



4.— Family: CUBOSPH^RIDA. Six radial spines oppo- 

 site in pairs. 



A. — TWO SPHERES. 



All six spines equal and simple. Hexalonche. 



B. — THREE SPHERES. 



All six spines equal and simple. Hexacontlum. 



5.— Family : ASTROSPH/ERIDA. P:igbt to twelve or more 

 radial spines. 



A. — ONE SPHERE. 



Spines all of same kind and simple. Acanthosphsera. 



B. — TWO SPHERES. 



All spines equal and simple. Haliomma. 



C. — THREE SPHERES. 



Spines equal. Adlnovwin. 



Larger and smaller spines. Eckmomma. 



XL— ELLIPSOIDAL SHELLS. 



Here are 19 genera which fall into 3 sections according to the 

 number of chambers. 



A. — One Chamber. 



C— Family: ELLIPSIDA One shell. 



Radial spines. Ellipsidium. 



No radial spines. CeacUipsis. 



Polar spines. Ellipsoxiphus. 



Spines at one {)ole only. Lithomespilus^ 



