146 Mr. Forbes on the Radiata of the Eastern Mediterranean. 



rated from the primaries. Another character, wliich greatly conduces to 

 the peculiar habit of the genus, is the form of the lateral ray-plates which lap 

 over each other and over a part of the superior and inferior ray-plates, and 

 bear spines on their superior margins. This character it shares with Pec- 

 tinura. The pectinated scales clasping the origins of the rays are peculiar 

 to this genus. The sources of specific character are, 1st, the number and dis- 

 position of the denticles of the pectinated scales ; 2nd, the form of the ovarian 

 plates ; 3rd, the form of the rays ; 4th, the form of the superior ray-plates ; 

 and 5th, the number of spines on the lateral ray-plates. The cirrhi in this 

 genus are simple. The revised characters of Ophiura and of the three species 

 inhabiting the vEgean Sea will stand as follows : — 



Genus Ophiura, Lamarck, Agassiz. 



Corpus orbiculare, squamosum, laeve, ad peripheriam radiatum ; radiis simplicibus, squamo- 

 sis in corporis discum prolongatis, ad origines squamis pectinatis adpressis ; squamis 

 lateralibus radiorum adpressis, in marginibus superioribus spiniferis : ossiculis ovaria- 

 libus marginis simplicibus, in corporis lobos productis. 



1. O. texturata, Lamarck, 



O. squamis pectinatis ad radiorum origines plusquam 20-dentatis, ossiculis 

 ovarialibus lyratis, radiis carinatis ; squamis superioribus transverse ob- 

 longis : lateralibus 7-spiniferis. 



2. O. albida, Forbes. 



O. squamis pectinatis ad radiorum origines 16-dentatis, ossiculis ovarialibus 

 scutatis, radiis convexis ; squamis superioribus triangularibus : laterali- 

 bus 4 — 5-spiniferis. 



3. O. ahyssicola, nov. sp., Forbes. Tab. XIII. fig. 8 — 14. 



O. squamis pectinatis ad radiorum origines binis 5 — 9-dentatis, ossiculis ova- 

 rialibus pentagonis, radiis carinatis; squamis superioribiis quadratis : 

 lateralibus 3 — 4-spiniferis. 



Lat. disc. -^-^ unc. 



