SCHIZASTER LACUNOSUS. 



S. japonicus with Linnets lacunosus, which I confess it is hard to do, the nom 

 species orbignyanus and edwardsi are so imperfectly known that it is diffi 

 to make a rational separation of the three forms. Mortensen thinks two spe 

 are confused under the name orbignyanus but while that is possible, I do 

 feel at all sure of it. The material accessible throws no light on these var 

 problems. I may add that Gray's Schizaster jukesii is probably a true Schiza.^ 



Key to the Species of Schizaster. 



Width of petal III one fourth of test-width or less; posterior petals little divergent, 

 distance between tips only about .30 of petal-length. 



Sternum narrow, its posterior width only about one half its length orbignyan 



Sternum broad, its posterior width about two thirds of its length . . . . . . lacunosus 



Width of petal III about one third of test-width; posterior petals strongly divergent, 



distance between tips more than .50 of petal-length edwardsi. 



Schizaster orbignyanus. 



A. Agassiz, 1880. Bull. M. C. Z., 8, p. 84. 



It is a puzzling fact that although Mr. Agassiz in his first report on 

 Blake Echini (loc. cit.) lists 11 stations where this species was taken, tl 

 are only three specimens in the M. C. Z. and only two of these are Blake sp 

 mens. One of these is a bare test, the holotype of the species (M. C. Z. ( 

 No. 2956), from off Barbados in 209 fms. ; it is figured in the final Blake Rep 

 pi. 28, figs. 1-4. The second is a young specimen from near Grenada in 

 fms. Our third specimen is a small crushed bare test found under a fragrr 

 of coral-rock, along shore, at Montego Bay, Jamaica. I can only account 

 the absence of material in our collection on the assumption that after the p 

 lication of the Blake Report, Mr. Agassiz found that some other spatanjs 

 had been confused with orbignyanus in making out the list of stations wr 

 the latter was taken. Mortensen (1907. Ingolf Ech., pt. 2, p. 117-119; 

 given a good summary of the difficulties to be faced in attempting to recogi 



