NO. 4 ziesenhenne: new eastern pacific sea stars 207 



Marginals regularly arranged, lateral; the plates of the two series of 

 the same size, roughly rectangular, and united in dorsoventral pairs by 

 the secondary ossicle which separates the papular areas. The plates of 

 each series are strongly imbricated, free edge adoral, and they also overlap 

 the interpapular secondary plates; superomarginals about 18, inferomar- 

 ginals 20. 



Actinal plates abruptly much smaller than inferomarginals, in 3 per- 

 fectly regular series, with the beginning of a fourth at interradius. They 

 also form regular transverse series of 3, two of these corresponding to an 

 inferomarginal. Actinal granules become gradually coarser toward fur- 

 row. 



Adambulacral plates compressed, somewhat crescent shaped, concave 

 distally, the actinal aspect about as broad as the furrow length of two suc- 

 cessive plates. Armature consists of a spatulate subtruncate furrow spine 

 with a shorter, much slenderer aboral companion; immediately behind 

 these (without intervening granules) stands a compressed, generally 

 abovate spine, about as long as the major furrow spine, and a secondary 

 aboral spinelet smaller than the corresponding one of the furrow series. 

 Back of these the plates are granulated as the adjacent actinals. Along 

 the margin of the extremely narrow furrow there are thus 2 series of 

 short, compressed spines (each with an inconspicuous companion). 



Madreporite subcircular, slightly concave, 2 mm. in diameter, with 

 numerous small pores but no obvious carinae. It is in contact with 2 inter- 

 radial superomarginals. 



Color. — Dried, light vinaceous buff. Color in life, abactinal surface 

 maroon with 2 purple longitudinal bands covering the papular areas, the 

 upper band terminating short of the ray tip and the lower band extend- 

 ing to the ray tip. Actinal surface creamish buff. 



Type.—ARY no. 41. 



Type /ocfl//7y.— Station 212-34, 45-50 fms., La Plata Island, Ecua- 

 dor, Februai-y 10, 1934. 



Remarks. — The rays of this specimen are unusually short. This con- 

 dition might be caused by a pathological disease or mechanical injury. 

 Many coral-dwelling fishes, especially the parrot fishes, are known to bite 

 off sea star rays and even stout sea urchin spines. Upon examination ter- 

 minal constrictions were noted suggesting regenerating ray tips. Com- 

 pared with Pharia and Phntoria, specimens in which ray tips were regen- 

 erating, the type differed by having short, blunt, and less tapering ray tips, 

 while the other specimens had longer, decidedly tapering ray tips term!- 



