NOTES ON GENERA. 125 



Genus STAURANDERASTER, 1 novum. 



PENTACKROS (pars). Pp. 76-89 of this Monograph. 



The species bulbiferus, Boysii, coronatus, ocellatus, bispinosus, pistilliferus, and 

 xi/iiiunatns (pp. 76 89 of this Monograph), which have been formerly placed in the 

 genus Pentaceros, together with the new species argus (p. 99), should, I think, 

 now be ascribed to a new genns. The plates of these species are breast-plate- 

 shaped, at times almost cross-shaped, and bear a characteristic type of ornament 

 ("see p. 113). In both these respects and in the absence of papular areas the 

 species differ widely from species of recent Pentaceros, with which the only feature 

 they have in common is the circlet of raised plates on the abactinal surface of the 

 disc. 



The type species of the new genus is Stauranderaster Boysii, and its diagnostic 

 characters are : 



Arms high, well produced, marginalia breast-plate-shaped, genei'ally with a 

 rabbet-edge free from ornament, and a raised interior area, either smooth or with 

 ornament of an embossed type. A circlet of swollen plates present on the 

 abactinal surface of the disc. 



This genus, with the following genus, may be placed provisionally in the family 

 PentacerotidaB. 



Genus HADRANDERASTER, 2 novum. 



PENTACEROS (pars), p. 86 of this Monograph. 



The species described as Pentaceros abbreviatus on p. 86 of this Monograph 

 differs so considerably in the shape of its marginalia and their ornament from the 

 species of Stauranderaster and recent species of Pentaceros that I have placed it in 

 a new genus. 



The type species is Hadranderaster abbreviatus, and the diagnostic characters 

 of the new genus are : 



Arms high, well produced, marginalia either hexagonal or rounded, very thick, 

 ornament spread uniformly over the surface of the plate. Pedicellaria bi-valvate. 



19 



1 crrai/pot = a cross, avStjpo v = a raised garden border. 



2 a'Spdj = stout, ni/%,01' = a raised garden border. 



