290 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Ophiozona longispina, sp. nov. 



Diameter of disc, 7-10 mm.; length of arm, 15-25 mm. Disc flat, covered by 

 about 60-75 plates, among which the central dorsal plate, the five radial primary 

 plates, and ten radial shields are conspicuous. Radial shields oval, much larger 

 than centro-dorsal, distinctly longer than wide, separated from each other by a lon- 

 gitudinal series of three or four radial plates. (Relative size and arrangement of 

 other dorsal plates decidedly variable.) — Dorsal arm-plates more or less diamond- 

 shape, two outer sides shorter than inner, with angles rounded (especially dis- 

 tal) or proximal truncate ; first three or more (even out to the seventh sometimes) 

 distinctly in contact. — Ventral surface of disc with interbrachial spaces covered 

 by 15-25 plates. Oral shields large (about 1 mm. each way), pentagonal, with 

 an inner angle, and outer side curved ; lateral sides nearly as long as inner. 

 Adoral plates somewhat variable, approximately quadrilateral but either broad or 

 narrow; distinctly in contact within. Genital plates moderately large and plainly 

 visible. Oral papillae four on each side, variable in relative size. No " infra- 

 dental" papilla. — Ventral arm plates more or less quadrilateral, at least at base of 

 arm, but becoming indistinctly pentagonal, hexagonal, or even heptagonal further 

 out ; first three or four wider than long, fourth or fifth about as long as wide, 

 remainder rapidly becoming much longer than wide : first 4-8 distinctly in contact. 

 — Side arm-plates rather small, coming in contact with each other dorsally at from 

 fourth to eighth arm-joint and ventrally at from fifth to ninth joint ; each one car- 

 ries two (rarely three) long, slender, acute, well-spaced spines, which are usually 

 longer than arm-joint and near base of arm, upper spine, which is longer than 

 lower, may equal two arm-joints. — Tentacle-scale single, of moderate size. — 

 Color (in alcohol) nearly white. 



3 specimens. Uraga Channel, Gulf of Tokyo, Japan; 70 fathoms. Owston 

 collection. 



List of the species of Ophiozona. 



pacifica Lutken, 1856. Vid. Med., p. 22. Pacific Ocean, off Mexico and Central 



America, littoral, 

 impressa Lutken, 1859. Add. Hist. Oph., pt. 2, p. 101. Atlantic Ocean off 



Elorida, West Indies, and Brazil, 0-300 fathoms, 

 nivea Lyman, 1875. Illust. Catal., 8, p. 9. Atlantic Ocean, off Florida and 



West Indies, 56-424 fathoms, 

 antillarum Lyman, 1878. Bull. Mus. Comp. Zool., 5, p. 127. Atlantic Ocean, 



off West Indies, 450 fathoms, 

 depressa Lyman, 1878. Bull. Mus. Comp. Zool., 5, p. 128. Pacific Ocean, off 



Meangis Islands, 500 fathoms, 

 dubia Lyman, 1878. Bull. Mus. Comp. Zool., 5, p. 224. Atlantic Ocean, off 



West Indies, 539 fathoms, 

 insularia Lyman, 1878. Bull. Mus. Comp. Zool., 5, p. 126. Pacific Ocean, off 



Fiji Islands. 310 fathoms. 



