46 



ASTEROIDEA. 



Second Family. 



, Two rows of tentacula in the ambulacral avenues. With a vent. 



2 Gemis. — Echinaster, M. and T. = Pentadactylosaster, Linck. 



Rays long, conical, or cylindrical; the skin supported on a network of calcareon'S pieces, 

 from which longer or shorter spines proceed, sometimes alone or set close together. Skin 

 between the spines naked, with many tentacule-pores. Vent subcentral. 



3. Genus. — Soi.aster, Forbes. 



Body stellate, multiradiate; rays 

 moderately long, and covered with fas- 

 ciculated spines; skin between the 

 spines naked, with many pores; no 

 pedicellarise ; vent central. 



Portion of a ray of Solaster papposa, Linn. ' A, the under ; 

 B, tbe upper surface. 



4. Genus. — Ch^taster, M. and T. 



Rays narrow and elongated, covered with plates which carry on their summits fascicu- 

 lated spines, single pores between the plates ; vent subcentral. 



5. Genus. — Ophidiaster, Agass. = Linchia, Nardo (pars). 

 Fig. 22. 



Rays cylindrical or conical, 

 everywhere covered with granular 

 plates ; many pores between the 

 plates, which are likewise surround- 

 ed by granules ; no pedicellariae ; 

 vent central. 



Section of a ray of Ophidiaster, with the inter-ambulacral plates. 



6. Sovi'ASTER, M. and T. = Pentadactylosaster, Linck. ; LincEa, Nardo. 



Rays elongated ; body stellate, everywhere covered with granular plates, which are 

 arranged on the margins in two rows ; the space between the plates likewise granulated. 

 The pores between the plates single. No pedicellarise ; vent subcentral. 



