neio Genera of Starfishes. 91 



bb. Papulae extending only one-seventh length 



of ray ; mouth-plates with comparatively 



few (5 or 6) marginal spines, regularly 



graduated in length toward inner teeth 



(fig. 2) ; dorsal muscle-bands stout and 



conspicuous Myonotiis, gen. nov. 



aa. Abactinal plates flat or convex, not tabu- 

 late, and though frequently lobed on papu- 

 lars areas, not strongly so, bearing a central 

 spine only, or several spinelets in addition, 

 or one to several small spinelets ; supero- 

 marginals usually with only one large 

 spine, and inferomarginals with one or two 

 primary spines; odd interradial marginal 

 prominent and usually present in all inter- 

 radii Benthopecten, Verrill. 



Neaechaster, gen. nov. 



Benthopectinidae with the odd interradial marginal plate 

 lacking in from one to four interradii, though sometimes 

 present in all; not always present in both series of the same 

 interradius ; abactinal plates large and small intermingled, 

 the larger primary plates bearing on a low tabulura a long 

 sharp spine surrounded by a circle of accessory slender 

 spinules, variable as to number and length — sometimes over 

 half as long as the primary spine ; secondary plates with a 

 group of shorter spinelets ; primary plates of papular areas 

 strongly stellate ; papula3 not in circumscribed areas, but 

 distributed all over disk (except sometimes the very centre) 

 and along ray from one-third to three-fifths its length, being 

 confined to either side of the paxillar area distally ; rays 

 very long and slender ; marginals extremely spiny — 2 or 

 3 long sharp superomarginal spines and 2 to 5" infero- 

 marginals ; subambulacral spines 1 to 3, usually 2, long ; 

 furrow-spines 1 to 7 ; mouth-plates large, with numerous 

 marginal spines, those of each pair of plates disposed in three 

 independent series ; the median teeth which are the largest 

 and fewest, and on either side a series of 8 to 12 smaller 

 spines, subequal or graduated in length toward the mesial 

 members of the group ; pedicellarige when present large, 

 pectinate, on any or all of the following plates : abactinals, 

 inferomarginals, actinal intermediates ; dorsal muscle-bands 

 not attached to an ambulacral ossicle, rather weak. 



Type, Acantharchaster aciculosus^ Fisher, 1910. 



Myonotus, gen. nov. 

 Benthopectinidai similar to Nearchaster^ but differing in 

 having the papulte confined to the disk and proximal seventh 



