200 A. M Verrill — Revision Genera and Species of Starfishes. 



Therefore, if this feature is to be the criterion, the Paxillosa 

 should only include such groups as never have true bivalve pedicel- 

 lariae. The existence of paxilliform plates on the dorsal surface can- 

 not be made an important character, for they occur in tyjjical forms 

 of Valvata. The development of terminal suckers on the ambulacral 

 feet varies much in both groups, and depends mainly on the nature 

 of the bottom inhabited. 



The Paxillosa would be a more natural group if limited to the 

 Poi'cellanasterida?, Astropectinidae, and the genus Archaster, while 

 the rest of the Archasteridfe (Sla.) might go into the Valvata (sens 

 ext.) However, it seems to me a more natural arrangement to con- 

 sider these groups as the two suborders of one order, equivalent in 

 rank to the three others proposed by Perrier. For this order 

 Sladen's name, Phanerozona^ might well be used, in a slightly 

 restricted sense, the Asterinidre and Gymnasterid^ being excluded. 



The classification of the order as now proposed would be as 

 follows: 



Order PHANEROZONA Sladen (rest.). 



Suborder I. — Valvata Perrier (sens ext.). 



Family 1. — Linckiid^ Perrier. 

 Family II. — Pentacerotid^ Gray (restr.). 

 Family III. — Antheneid^ Per. (restr.). 

 Family IV. — Goniasterid^ Forbes (restr.). 



Subfamily I. — Goniasterina? V., nov.=Pentagonasterin8e Sla. 

 i^pars). 



Subfamily II. — Goniodiscina; Sla. 



Subfamily III. — Mediasterinae V., nov. 



Subfamily IV. — Pseudarchasterinfe Sla. 



Subfamily V. — Hippasteriinse V., nov. 

 Family V.— Odontasteridje Ver. nov. = Gnathasterinje Per.(joars). 

 Family VI. — Plutonastbrid^e Ver. 



Subfamily I. — Mimasterinte Sla. 



Subfamily II. — Plutonasterinae Sla, 



Subfamily III. — Pontasterinae Ver., 1894. 

 Family VII. — Goniopectinid^ V., nov. 

 Family VIII. — Benthopectinid.e V. = Benthopectininw Ver., 1894. 



