RECENT OPHIURANS. 271 



816. 0. DYSCRITA, sp. nov. (Suo-xpiros, hard to determine). Plate 13, f. 3. 



Disk 2 mm. in diameter; arms 20 mm. long, becoming moniliform distaUy. 

 Disk covered with minute scales which carry low and slender 3-pronged spine- 

 lets; these are largest and most crowded in the interradii at and below the disk- 

 margin. Radial shields large and more or less bare but not clearly defined. 

 Upper arm-plates diamond-shaped, longer than wide (except the basal ones), 

 in contact only at base of arm and widely separated distaUy; the distal angle 

 tends to become swollen and more or less projecting on the moniliform part of 

 arm. Oral shields two or tlii-ee times as wide as long and adoral plates very 

 long and narrow. Under arm-plates long, becoming much longer than vnde, 

 quadrilateral with distal margin markedly concave, broadly in contact. Side 

 arm-plates large and conspicuous, especially distaUy, meeting broadly above; 

 each carries 4 or 5 very slender and very thornj^ arm-spines; the next to the 

 uppermost is usually longest and nearly equals three arm-joints. Color (in life, 

 and also dried), pale purple above, without markings; whitish beneath. 



HoLOTTPE (M. C. Z. 3798) . Torres Strait : Murray Islands, Mer, off south- 

 western reef, 18 fms., in a sponge. Oct. 13, 1913. Carnegie Exp. 1913. H. L. 

 Clark coU. 



Although most of the characters shown by this specimen indicate very early 

 youth, it entirely lacks the large central plate of the disk, which is so characteristic 

 of young Ophiothrix. It has been carefully compared with young stelligera 

 of the same size and with the young of many other species, but there is none to 

 which it can be referred. The difficulty of determining single, small specimens 

 of Ophiothrix is exceptionally great however (hence the name) and I do not feel 

 satisfied that this specimen wdll not prove to be the young of some previously 

 known species.- 



817. O. ECHINATA (Delle Chiaje). 



Asterias echinata Delle Chlue, 1828. Mem. anim. sans Vert. Xapoli, 3, p. 74, 78, pi. 34, f. 5-8. 

 Ophiothrix echinata MtjLLEE and Troschel, 1840. Arch, naturg., 6, p. 329. 



79 specimens. Mediterranean Sea. Trieste. Naples. Nice. Algeria: 

 Oran. 



818. O. ELEGANS LtjTKEN, 1869. Add. ad hist. Oph., pt. 3, p. .57, 99. Koehler, 1904. Mem. Soo. 



zool. France, 17, p. 110, f. 82-86. 



1 specimen. Pelew Islands. 



819. 0. EI'STEIRA H. L. Cl.\ek, 1911. Bull. 75 U. S. X. M., p. 265, f. 132. 



1 PAEATYPE. Japan: Ousima. 



