92 



On two new Genera of Starji-ihes, 



o£ ray, in the comparatively few marginal moutli-spines, 

 regularly graduated in length toward the inner teetli^ and in 

 the very stout dorsal muscle-bands ; marginal plates very 

 spiny (2 or 3 superomarginal and at least 3 inferomarginal 

 spines) ; primary abactinal plates of papular areas strongly 

 lobed and in the form of tabulate paxilla?, bearing a large 

 central spine, and a circle of small spinelets on the tabulum ; 

 odd interradial marginals present in all interradii, the unpaired 

 superomarginal not conspicuously larger than neighbouring 

 plates, and its spines not larger than succeeding supero- 

 marginal spines ; adambulacral furrow-spines 1 to 3, long ; 



subambulacral s 



pines 



Type, Acayithar chaster intermedins, Fisher, 1910. 



Fig. 1. 



Fig. 



Fig. 5. 



Fig. 1. Mouth-plates of Near chaster nciculosus. x 3. 



2. Mouth-plates of Mrjonotus intermedins, x 3. 



3. Seventli superomarginal plate of Nearchaster aciculosus, from 



above. X 3. 



4. Eighth adambulacral plate of Myonotus intermedins : /, furrow- 



spines. X 3, 



5. Abactinal paxillae of Nearchaster aciculosus. x 3. 



II 



