MONOGRAPH OP JAPANESE OPHIUROIDEA. 79 



tubercles on the entire dorsal surface of the disk. In distinguish- 

 ing A. dofleini from the coniferus and pardalis type, Döderlein 

 seems to lay weight upon the fact that, the granules of the 

 arm bases of the former have no acute tips, but are smooth. 

 But, one of my specimens, measuring 55 mm. across the disk, 

 has very abundant hemispherical tubercles on the arms and 

 easily recognizable acute granules on the arm bases, the latter 

 being distributed as far out as the fifth bifurcation. The colour 

 of the same specimen is simply deep purplish black, and the disk 

 coverings are almost similar to those of the coniferus type, though 

 the conical tubercles on the radial ribs near the outer ends are 

 not present. 



Key to Japanese species of Astrohoa. 



A — Madreporic shield lying at the inner angle of the interbrachial 



ventral surface. 

 a — Annulations of double rows of hook-bearing granules distinct even 

 in the stout proximal parts of arms ; colour purphsli black . . nigra, 

 aa — Annulations of double rows of hook-bearing granules absent in the 

 stout proximal parts of arms; colour dark grayish brown. . .arctos. 

 AA — Madreporic sliield lying on the hard part just inside the inter- 

 brachial ventral surface, being almost free from the latter ; colour 

 light pinkish brown glohifera. 



Astroboa nigra Döderlein. 



Astropliyton davatmn : Pfeffer, Mitteil. Naturh. Mus. Hamburg, XIII, 

 1896, p. 48.^) (Non Lyman.) 



Astroboa nigra : Döderlein, Abh. Math.-Phys. 111. K. Bayer. Akad. 

 Wiss., Suppl.-Bd. I, 1911, p. 83, PI. IX, figs. 9 & 9a. 



1) This paper was not seen by me. 



