GENEBA AND GROTIPS OF THE ECHIN"OIDEA. 



293 



Division Apetala, p. 266. 



Section Adcfes, p. 266. 



Genus 

 Genicopatagus, p. 266. 

 PaliBobrissus, p. 268. 



Section Pryvmadetes, p. 269. 



Genus 

 Aceste, p. 269. 

 Aerope, p. 271. 



Section Fryinnodesmia, p. 273. 



Genus 

 Ovalaster, p. 273. 



Genus 

 Palffiotropus, p. 273. 

 Homolampas, p. 275. 

 Argopatagus, p. 276. 

 Oleistechinus, p. 277. 



Family LESKIID^E, p. 278. 



Genus 

 Palseostoma, p. 278. 



Family POTIRTALESIID^, p. 279. 



Genus 

 Pourtalesia, p. 284. 

 Spatagocystis, p. 286. 

 Echinocrepis, p. 287. 



Total geuera , 255 



Subgenera 50 



Divisions 6 



311 



These include 12 new genera and 7 new subgenera. 



Sub gen. 34 



Divisions 5 



The extinct genera are 161 

 The genera with extinct > 

 and existing species . . 41 | 



The genera with recent or i 

 existing species only . . 53 J 



255 



!-94 



9 

 7J 

 50 



U6 



Genera synonymous with recognized types or abolished 108 

 „ placed as subgenera 42 



150 



The following genera have been considered to be superfluous or 

 synonyms of others : — 



Grenus Palceocidaris, PeriscJiocidaris, EcTiinocrinus, Proto- 

 echinus, Typhlecliinns, Melechinus, Xenocidaris (spines only), 

 Cystocidaris, Palceodisctis. 



Grenus Wmhdocidaris, Leiocidaris, Dorocidaris, Stephanocidaris, 

 PJiyllacanthus, Porocidaris. (These are now divisions of Gidaris.') 



