116 THE VOYAGE OF H.M.S. CHALLENGER. 



Ophiactis asperula, Ltk., Addit. ad Hist., part 2, p. 130, 1859. 



Ophiolepis asperula, Phil., Wcig. Archiv, p. 267, 1858. 



Ophiactis magellanica, Ljn., Om nagra nya arter, Of. Kong. Akad., 186G, p. 164 ; Oph. Viv. Of. 

 Kong. Akad., p. 325. 



AVest and south-east coasts of Patagonia ; 44 to 315 fathoms. Chili; 44 fathoms. 

 Station 308.— January 5, 1876 ; lat. 50° 10' S., long. 74° 42' W. ; 175 fathoms; mud. 

 Station 311.— January 11, 1876; lat. 52° 50' S., long. 73° 53' W. ; 245 fathoms; mud. 

 Station 312.— January 13, 1876 ; lat. 53° 38' S., long. 70° 56' W. ; 10 to 15 fathoms; 

 mud. Station 315.— January 26, 27, 28, 1876 ; lat. 51° 40' S., long. 57° 50' W. ; 5 to 

 12 fathoms ; sand and gravel. 



Ophiactis fiexuosa, Lym. (PI. XX. figs. 1-3). 



Ophiactis fiexuosa, Lym., Bull. Mus. Corup. Zool., vol. vi, pt. 2, p. 37, pi. xiii. figs. 347-349, 1879. 



Disk scales distinct and naked, without spines. Three stout, blunt, tapering, cylindrical 

 arm spines. One large, flat mouth papilla on each side. Teeth lobed. Five arms. 



(Type specimen from Station 171.) Diameter of disk 7 mm. Length of arm about 

 35 mm. Width of arm near disk 2'3 mm. Each side of the short, narrow mouth angle 

 is occupied by a single very large, wide, flat papilla, while a third, standing under and 

 resembling the teeth, is at the apex, and has a rounded figure, with a decided peak or little 

 lobe within. Mouth shield somewhat broader than long, of a rounded diamond shape. 

 Side mouth shields rather broad, wider without than within where they meet. First under 

 arm plate small, and wider within than without ; those beyond are narrow compared with 

 the width of the arm, much rounded, of a short transverse oval shape, with the inner side 

 somewhat angular. Side arm plates very wide, meeting neither above nor below, and 

 having but a feeble lateral projection. Upper arm plates broad and short, two and a half 

 times as wide as long, of an elongated transverse diamond form, sometimes with outer side 

 so straight as nearly to be triangular. Disk without spines, and covered above with coarse, 

 rounded, thick, overlapping scales, of which there are four or five radiating rows in the 

 narrowest part of each interbrachial space. Below, the scales of the interbrachial space 

 are much finer (four or five in the length of 1 mm.), and regularly imbricated. Three 

 short, stout, cylindrical, scarcely tapering arm spines of nearly equal length, and about 

 as long as one and a half joints ; the upper spine stoutest. One large oval tentacle scale. 

 Colour in alcohol, pale brown. 



Station 171.— July 15, 1874; lat. 28° 33' S., long. 177° 50' W.; 600 fathoms; rock. 

 Station 142.— Dec. 18, 1873; lat. 35° 4' S., long. 18° 37'E.; 150 fathoms (young?); sand. 



The ten specimens from Station 142, 150 fathoms, may be the young of this species. 

 They have six arms, while Ophiactis fiexuosa has but five, and are scarcely to be distin- 

 guished from Ophiactis plana ; and the question arises whether Op>hiactis plana be not a 

 young animal. The so-called adult of Opjhiactis miilleri has five arms, and the young six. 



