the Genera and Species of Starfish. 183 



See also Ast. pentacantha, Ast. spinulosa, Ast. platycantha, Ast. 

 subinermis, Philippi, (but this author considers the number of the 

 marginal tubercles, which increase with the age of the specimen, as a 

 specific character,) and Asterias calcitrapa, Lam. 



b. The rays without any large tubercles on the margin. 



3. Luidia, Forbes. *-~" Yf 

 Margin of the 5 flat rays erect; the dorsal surface crowded with 

 regular paxilli. 



1. Luidia fragilissima, Forbes in Wern. Trans. 1839, 14. — Asto,- *r > 

 rias rubens, Johnston in Mag. H. N. 144. f. 20. 



Inhab. North Sea. 



2. Luidia Savignii, Gray. Ast. Savignii, Audouin in Savigny, 

 Egypt, Echinod. t. 3. 



Inhab. Red Sea. 



3. Luidia} ciliaris. Asterias ciliaris, Philippi in Wiegm. Arch. '' 



1837, 19. 



Inhab. Sicily. . _, _ 



4. Petalaster, Gray. 



Margin of the rays shelving ; the dorsal surface with equal paxilli 

 placed in longitudinal and cross series. Asiatic. 



1. Petalaster Hardwickii, Gray. Rays elongated, rather slender, 

 tapering at the end ; the dorsal tubercles with small truncated spines, 

 and a distinct series of rudimentary spines. 



Indian Ocean. 



2. Petalaster Columbia. Rays elongated, slender, gradually taper- 

 ing; tubercles short, with crowded groups of rather large acute 

 spines, and a fringe of very fine radiating ones. 



Inhab. St. Bias. H. Cuming, Esq. 



B. The margin of the rays not edged with large tubercles, simple, or 

 ciliated with short broad spines bearing tubercles. 



5. Sol aster, Forbes, ft* "V-i 

 The rays many, with 2 series of broad spines bearing tubercle* 

 near the ambulacra. 



a. Body 8 or 9-rayed t closely reticulated, rays rounded, ventricose 

 below, tapering at the tip, with a second row of compressed tubercles 

 on the under side of the arms near the amlulacral series. Endeca, Gray. 



1. Solaster Endeca, Forbes. Asterias Endeca, Linn. Ast. aspersa, 

 Muller. 



Inhab. European Ocean. 



b. Body 10 or 12-rayed, loosely reticulated; the rays depressed, 

 with a series of large compressed tubercles crowned with a bunch of 

 spines edging the oral ridge. Potyaster, Gray. 



2. Solaster papposa, Forbes. Asterias papposa, Linn. Ast. stel- 

 lata, Retz. 



Inhab. European Ocean. 



