48 VERRILL 



Genus Orthasterias Verrill, nov. 



Rays long, usually five, bearing three, five, or more dorsal rows 

 of rather long spines, besides a superomarginal row on each side. 



Inferomarginals bear each one or two spines, usually two. One 

 row of interactinal or peractinal plates, with or without spines, close 

 to the adambulacrals ; the latter are diplacanthid ; a short subactinal 

 row may also occur rarely. 



Lateral and dorsal dermal pedicellarise are large, partly wedge- 

 shaped or spatulate, often dentate, or unguiculate. Type, O. colum~ 

 biana Ver., sp. nov. Also includes O. dawsoni Ver., nov. ; 0. tanneri 

 Ver. ; O. biordinata Ver.; O. calif arnica Ver., etc. 



Subgenus Stylasterias Verrill, nov. 

 Type, S. forreri Lor. 



Dorsal plates in the adult usually in three regular rows, having 

 elongated spines. Upper and lower marginal plates large and 

 regular, with a well marked channel between, crossed by the large 

 descending apophyses of the upper plates, and carrying papulae and 

 large forficiform pedicellarise. Lower marginal plates close to the 

 adambulacrals, each bearing one or two long spines. Peractinal 

 plates lacking or rudimentary; when present never bearing spines, 

 and so small as to be easily overlooked, without dissection. Adam- 

 bulacral spines diplacanthid. 



Among other species that belong to this group are the following : 



S. enopla Ver., off Nova Scotia. 

 S. neglecta (Per.), East Atlantic. 

 S. contorta (Per.), West Indies. 



Genus Cosmasterias Sladen, 1889. 



This name was proposed for the group having as the first species, 

 Asterias (Cosmasterias) tomidata Sladen (op. cit, pi. cv, figs. 8-10), 

 and including also Asterias sulcifera Perrier, 1869 = C. lurida (Phil- 

 ippi), 1858. 



Perrier has adopted Cosmasterias with C. sulcifera 1 (Per.), from 

 off Patagonia, etc., as the type. 



The genus is diplacanthid and has several regular rows of inter- 

 actinal spines, but it has large, unguiculate or felipedal, dermal, 



1 For full synonymy and new descriptions of this species and C. tomidata, 

 see Leipoldt, Asterioidea der Vettor Pisani Exped., 1895, PP- 552-563. See, also, 

 below, under Geographical Distribution. 



