893 



ECHINODERMATA. 



Pbtrastbr bbllulus. (N. sp.) 



Fig. 368. 

 Fig. 368. — Petraster bellulus. Under side. 



Description. — Deeply stellate, about eighteen lines across ; disc five lines 

 •wide ; width of rays, at the base, half the -width of the disc, uniformly 

 tapering to their extremities ; ambulacra! grooves, narrow and deep, with 

 about thirty adambulacral plates on each side. These plates are strongly 

 convex and nearly square. Outside of these there is a row of marginal 

 plates, which appear to extend to the extremities of the rays, but on this 

 point there is doubt, as the specimen is not perfect. There appear to be 

 one or two small disc plates between the marginal and adambulacral plates 

 just outside of the oral angles. 



Locality and Formation. — Township of Grimsby ; in the Niagara shale. 



Collector. — Johnson Pettit, Esq., Grimsby, C. W. 



Ctclocystoidbs Htjronensis. (N. sp.) 



Fig. 369. 

 Fig. 369. — Cydocystoides Huronensis. 



Besmption. — The only specimen of this species that has been collected 



AA 



