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



Opliiactis simplex, Ltk. {Ophiolepis), Atldit. ad Hist., part 2, p. 130, 1859 ; Lyrn., 

 111. Cat, Mus. Comp. Zool., No. i. p. 105. 



Ophiolepis simplex, Le Conte, Proc. Phil. Acad., vol. v. p. 318, Nov. 1851. 

 Ophiactis Orstedii, Ltk., Addit. ad Hist., part 2, p. 129, 1859. 

 Opliiactis arenosa (?), Ltk., Addit. ad Hist., part 2, p. 129, 1859. 



West Coast Central America. 



Ophiactis arenosa, Ltk., Vid. Meddel., p. 25, March 1856 ; Addit. ad Hist., part 2, 

 p. 129. Vll., Trans. Conn. Acad., vol. i., part 2, p. 266. 

 West Coast Central America. 



Ophiactis kroyeri, Ltk., Vid., Meddel., March, 1856, p. 24 ; Addit. ad Hist., part 2, 



p. 130; Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 108; Vll, Trans. Conn. Acad., 



vol. L, part 2, p. 264. 



Ophiolepis atacamensis, Philippi, Keise durch der Wueste Atacarua, p. 190, 1860. 

 Ophiactis atacamensis, Ljn., Oph. Viv. Of. Kong. Akad., p. 324, 1866. 



Ophiactis fragilis, Ljn., Om nigra nya arter, Oph. Of. Kong. Akad., p. 164, 1866 ; Oph. Viv. 

 Of. Kong. Akad., p. 324, 1866. 



Isla Blanca, Chili ; West Coast of Central America ; Hawai. 



Ophiactis nigrescens, Hutt., Ech. New Zealand, 1872, p. 2. 

 New Zealand. 



Ophiactis maculosa, v. Mart., Wieg. Archiv, vol. xxxvi. p. 248, 1870. 

 China Sea. 



Ophiactis dbyssicola, Ljn., Oph. Viv. Of. Kong. Akad., p. 324, 1866. 



Amphiura ahyssicola, Sars, Oversigt Norges Echin., p. 18, 1861. 

 Ophiocnida ahyssicola, Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 12. 



Norway; 190 to 400 fathoms. 



Amphiura. 

 Amphiura, Fbs., Linn. Trans., vol. xix., 1842. 



Disk small and delicate, covered with naked, overlapping scales, and furnished with 

 uncovered radial shields. Teeth. No tooth papdlas. Mouth angles small and narrow, 

 and bearing a few (usually four or six, rarely eight or ten) small mouth papillas. Arms 

 long, slender, even and more or less flattened. Arm spines short and regular. Two 

 genital openings to each interbrachial space. 



Ampihiura bellis gives a good type of this generic structure. The disk wall is cased 

 with fine, regular, overlapping scales and large, flat, elongated radial shields, having at 

 their outer end a small knob which marks their articulation to the long, slender, flattened 

 club-headed genital plate. To this last is fastened an equally long, slender, bladedike 



