188 NATURAL HISTORY BULLETIN 



The dorsal plates are rounded, decidedly convex above, with 

 about six basal lobes, which unite by overlapping, leaving about 

 six simple papular pores around each plate, except on the disk, 

 along the median row, and on a small interradial area, where 

 papulae are lacking and the plates are more closely joined. 



The dorsal plates are protopaxillse, bearing many small, short, 

 divergent spinules on the convex portion, but not forming 

 f ascioles. On the disk and base of the rays there are a few small 

 interpolated plates. 



A single row of plates separates the superomarginals distally 

 in the type. There are no well-marked fascioles between the 

 superomarginal plates. The marginal plates are thick, convex, 

 regularly paired, somewhat oblique distally. The superomar- 

 ginals are granulated or minutely spinulated. The inferomar- 

 ginals are spinulated and also, in the type, bear a few larger 

 spines in a submarginal transverse row. Grooves between the 

 plates are shallow and have only poorly developed fascioles. 



The interactinal plates form series subparallel to the adambu- 

 lacrals, but there are a few unpaired plates in the median inter- 

 radial line. The interactinal plates are tesselated, somewhat 

 convex, roundish or subpolygonal, and bear divergent spinules 

 that do not form evident fascioles nor regular radial rows. 



The adambulacral plates are somewhat oblique, with an angu- 

 lar inner end, which bears a row of four to six spines ; the actinal 

 surface is covered with small divergent spinules, not f asciolated. 



Jaws stout and convex, covered on the actinal side with spine- 

 lets, and with a row of about nine longer spines on each side. 

 The peroral spines, in a pair, are larger. 



The pedicellarige are small, papilliform, with three to six valves 

 surrounding a small pit in the plate. They are often lacking. 

 Superambulacral plates are present. A small dorsal pore was 

 present in some of the specimens examined by me. 



Professor Fisher has given (op. cit., 1911) a more detailed de- 

 scription of the type of this genus, wdth photographic figures. I 

 have also studied the type, as well as several other specimens. 

 No other species is known, unless Bunodaster ritteri Ver., of Cal- 

 ifornia, be considered congeneric, as Fisher suggested (1911&, 

 p. 40). 



Bunodaster differs from Blakiaster by its less massive and dif- 

 ferently shaped marginal plates, which are less complex and 



