2^^^ 



1034 DK. J. W. GREGOEY ON THE CfASSIFICATION [DeC. 15, 



Type species.- — Bundenhaclda heneckei, Stiirtz. 



llemarlcs. — The diagnosis of this genus is based on specimens in 

 tlie British Museum received from Herr Stiirtz. The diagram 

 (fig. 4) has been prepared from specimen B.M. No. E 3495. 



Kg. 4. 



Ml ^ 



Ijundcnbachia : aim-structure. 



Bundenhachia differs from Protaster by the irregular nature 

 and soft plating of the disc, by the presence of spine-bearing 

 plates attached to the adambulacral ossicles, and by the different 

 form of the ambulacral ossicles. 



Family 2. PAiiiEOPiiiuiiiflas. 



Dia(/nosis. — Lysopliiura) in which tlie ambulacral ossicles aro 

 long and bar-slinped, with the longer axis parallel to tlio arm. 



llemarhs. — This family agrees with the Protasteridu) in not 

 having the ambulacral ossicles of each segment placed opposite 

 one another. It differs by having the ambulacral ossicles longer 

 than wide, and never divided transversely by muscular depressions. 

 The ambulacral ossicles are either bar-shaped or thickened to a 

 subquadrate form. They are never boot-shaped. 



Genus 1. Pal.teopuiuba, Stiirtz, 1890 [16. p. 233]. 



Diagnosis. — Pala3ophiurida3 with the disc surrounded by rod- 

 shaped marginal ossicles. The ambulacral ossicles are rods lying 

 parallel to the arm. 



Distribution. — Lower Devonian, Bundenbach. 



Type species. — Palaiophiura simplex, Stiirtz. 



Q-enus 2. Stfutzuba, nov. gen. 



Diagnosis. — Palajopliiuridoe Laving thick, subquadrate, ambu- 

 lacral ossicles and narrow adambulacral plates. The disc is fragile, 

 and its plates are small and thin : it has no marginal plates. The 

 month-frames are narrow and separate. 



Distribution. — Silurian, England and Australia. 



Type species. — Sturtzura brisinyoides (Gregory), 1889 [5]. 



liemarks. — This genus differs from Paliieoiihiura, as the ambu- 

 lacral ossicles are thick and subquadrate, instead of being in the 



