248 ECHINODERMA OF THE INDIAN MuSEUM. PART VIT. 



DEOAMETROCRINUS RUOOSUS. 



Decametrocrinns rugosx.^ 1908. A. H. Clark. Proc. U. S. Nat. Mus., vol. 34, 

 p. 215. 



Habitat. — Hawaiian Islands. 

 Depth.— 762-1000 fathoms. 



DECAMETROCRINUS NARESI. 



Prnmachoerinus naresi 1888. P. H. Carpenter. "Challenger" Reports, vol. 26, 



Zo6logj\ p. 352, pi. Ixix, figs. 8-10. 

 Decametrocrimifi horealis 1907. A. H. Clark, Proc. U. S. Nat. Mus., vol. 33, 



p. 71. 



Habitat. — Meangis Islands, and northward to southern Japan. 



Depth. — 3*) 1-500 fatlioms. 



DECAMETROCRINUS ABYSSORUM. 



ProDiachorrinuft ahijssorum 1888. P. H. Carpenter. "Challenger" Reports, 

 vol. 26, Zoology, p. 351, pi. i, figs. 4, 5; pi. Ixix, figs. 5-7. 



Decametrocrinvs abijssorH.ni 1905. Minckert, Zool. Anzeiger, vol. 28, p. 494. 

 Habitat. — Extreme southern part of the Indian Ocean. 

 Depth.— IfiOO- 1800 fathoms. 



DECAMETROCRINUS sp. 



Locality. — "Investigator" Station No. 124. 



Remarks. — A single ineomplete arm of a large species of Decametrocrinus 

 was dredged at this station. It is broken into eight fragments, all of which 

 except one evidently belong in a linear series. The basal portion is 4 mm. 

 in diameter, and the total length is 278 mm.; it is probable that at least 50 

 mm. of the basal part is missing, and 40 mm. of the tip, so that the arm length 

 must have been nearly or quite 350 ram. This would give an expanse of 700 

 mm., and indicate a size approximate to that of Heliovietra maxima, previously 

 the largest known crinoid, recent or fossil, which T dredged in abundance about 

 the southern end of Sakhalin Island in 1906. 



The genital glands in this specimen, instead of being ovoid or fusiform 

 bodies as in other comatulids, are broken up into a series of small bead-like 

 bodies, approximately one to each of the greatly elongated pinnulars, and are 

 protected by prominent calcareous plates. This may be a sexual dift'erentiation 

 but it appears more probable that it is in reality specific, and, taken in con- 

 nection with the very large size and the intersyzygial interval of four or five 

 oblique muscular articulations, it certainly dififerentiates this specimen sharply 

 from the few other more perfect individuals heretofore known. Until more is 



