GENEEA AND GHOUPS OF THE ECHINOIDEA. 45 



III. 



The Suborder Stereosomata and its Families. The Family Saleniidse and its 

 Genera. Family Hemicidaridte and its Genera. Family Diadematidje ; its 

 Subfamilies and Genera, Genus incertce sedis. Family Cyphosomidse and 

 Genera. Family Arbaciidae and Genera. Family TemuopleuridEe ; Subfamilies 

 and Genera. 



I. Family SAijENiii)M,Duncan and Sladen, 1887, Ann. Sf Mag. 

 Nat. Hist. ser. 5, vol. xix. p. 117. 



Eegular ectobrancliiate gnatbostomes, with a persistent dorso- 

 central plate or plates ; madreporite in the right anterior basal 

 plate. Ambulacra narrow, the plates numerous, simple low 

 primaries, rarely in compound plates actinaUy. Interradial plates 

 few and tubercles large. Peristome with branchial incisions and 

 external branchiae. Perignathic girdle with interradial ridges and 

 ambulacral processes united or not. Jaws with the foramina of the 

 pyramids unarched by epiphyses ; teeth with a keel. Spheridia 

 present. Spines very variable, cellular with a solid superficies. 



Division I. 



Genus Feltastes. 



Syn. Hyposalenia ; Pseudosalenia ; Poropeltis. 

 Subgenus Goniophorus. 

 Genus Salenia. 



Subgenus Heterosalenia. 



Division II. 



Genus Acrosalenia. 



Division I. 

 Ambulacral plates simple. 

 Genus Peltastes, Agassiz, 1838, Monogr. d'Ech. viv. et foss. 

 livr. i. p. 27, pi. V. (non Desor, 1858, Synopsis, p. 145). 

 Duncan Sf Sladen, 1887, Ann. Sf Mag. Nat. Hist. ser. 5, 

 vol. xix. pp. 129-132. {Amended.) 



