1915.] NATURAL SCIENCES OF PHILADELPHIA. 65 



the surface is so convex that they appear Hke hemispherical tubercles. 

 Arm spines five in number on proximal joints, but four distally; 

 they are conical, blunt, solid, terete; dorsal ones longer and stouter; 

 uppermost about one and a half times, and lowest about two-thirds, 

 as long as corresponding arm joint. Tentacle scales absent. Color 

 in alcohol: yellowish brown. 



Numerous specimens; Okinose (a submarine bank), Sagami Sea. 



In younger specimens, the skin, which covers the disk and arms, 

 is very thick and the buccal pores are often indistinct. 



Family 2. HEMIEURYALID^E Verrill, 1899 (emend.). 



(Characters as given in key, p. 62.) 



Key to subfamilies of HemieuryalidcB. 



A — Dorsal arm plates entire, without supplementary plates; lateral 

 arm plates usually in contact above and below; five to eight 

 arm spines, moderately long, conical; no proper tentacle 

 scales, but lowest arm spine may serve as one, 



Ophiochondrin^. 



AA — Dorsal arm plates often accompanied by secondary plates or 

 replaced by a mosaic of small plates; lateral arm plates 

 usually separated above and below; three arm spines and one 

 tentacle scale, all very short and flat Hemieuryalin^. 



Subfamily 1. OPHIOCHONDRIN^ Verrill, 1899 (emend.). 

 (Characters as given above in key.) 



This subfamily includes Ophiochondrus, Ophiomoeris and Ophio- 

 gyptis. 



Ophiomoeris projecta sp. nov. 



This species closely resembles Ophioceramis f ohstricta Lyman 

 (= Ophiomoeris ohstricta Koehler, 1904 = Ophiurases obstrictus Clark, 

 1911), but differs in two important points. The radial shields are 

 distinctly joined in pairs distally for half their length. A number 

 of large, prominent, spherical tubercles are present on the disk, 

 irregularly arranged along the distal margin of the radial plates, along 

 the joining line of each pair of radial shields, and often also along 

 the outer borders of the same. In the last character, the present 

 species reminds us of Ophiogyptis nodosa. The type specimen 

 measures 4 mm. across the disk, 13 mm. in the arm length and 1.5 

 mm. in the arm width at base. Color in alcohol: disk gray, arms 

 banded with grayish browTi and white. 



Two specimens; off Ukishima, Uraga Channel; 300 fathoms. 

 One specimen; off Ujishima, Osumi. 

 5 



