Mr. J, W. Salter on some new Paheozoic Star-fishes. 329 



spines exceeds any known species, recent or fossil. It is in 

 many respects like P. Marstoni. 



There is another species very like P. Marstoni, but with slen- 

 derer and less closely reticular arms, much longer in proportion, 

 clothed with delicate short spines, and with a thin, membranous, 

 inter-radial web. It may be called P. cygnipes, and be thus 

 characterized : — 



3. P. cygnipes, sp. nov. 



P. 2 l^-uncialis, tenuis, disco membranaceo expanse ; brachiis elongatis 

 brevi-spiuosis ; ore parvulo rosaceo. 



Same locality as the last. 



Subgenus Bdellacoma. 



4. P. [Bd.) vermiformis, n. sp. 



P. brachiis longis linearlbus, brevi-spinosis, tuberculis clavatis remotis; 

 assulis ambulacri lati alternatis, remotis, iutervallis rotundis. 



Differs from both the preceding by its short spines, long arms, 

 and wide, flat, ambulacra! avenues with large alternating apertures 

 for the suckers. It is doubtful if these avenues are bordered 

 by more than a single row of plates ; but as there is a double 

 set of tufts of spines, this is probable. 



The main character of the species, however, and that which 

 distinguishes the subgenus, is the possession of scattered clavate 

 tubercles over the upper surface. These are nearly as long as 

 the spines. The ambulacral avenues, too, appear to differ ma- 

 terially from those of Palceocoma, in which they are remarkably 

 narrow and the plates close, while in Bdellacoma they are broad 

 and the ossicles remote. 



So much depends, however, on the state of preservation in 

 these shale fossils, that I do not feel warranted at present in 

 ranking Bdellacoma higher than as a subgenus. The ambulacra 

 are -not clearly seen. 



Loc. Leint war dine. 



Subgenus Rhopalocoma. 



5. P. {Rh.) pyrotechnica, n. sp. 



P. 2^-uncialis, pentagona ; brachiis brevissiniis reticulatis ; sj)inis 

 brevibus clavatis compressis. 



The subgeneric and specific characters of this fine species 

 must be taken together, and reside in the distribution of short, 

 broad, clavate and compressed spines over the upper surface 



