REPORT ON THE OPHIUROIDEA. 159 



thicker than in Amphiwa, and have no upper outward projection. Their under surface 

 has a very large canal (fig. 5, t), but not so high nor so wide as in Hemipholis. 

 See Plate XL. figs. 4-7. 



Species of Ophiophragmus not herein described. 

 Ophiophragmus wurdemani, Lym. (PI. XL. figs. 4-7). 



Ophiophragmus Wurdemani, Lym, 111. Cat. Mus. Com p., Zool., No. i. p. 132, 1865. 

 Amphiura Wurdemani, Lym., Proc. Bost. Soc. Nat. Hist., vol. vii. p. 1G9, 1860. 



West Coast of Florida. 



Ophiophragmus marginatum, Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 131, 1865. 



Amphiura marginata, Orst. & Ltk., Vid. Meddel., March 1856, p. 26 ; Addit. ad Hist., part 2, 

 p. 119, pi. iii. fig. 3, 1859. 



West Coast of Central America. 



Ophiophragmus septus, Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 12, 1865. 



Amphiura sepia Ltk., Addit. ad Hist., part 2, p. 120, 1859. 



West Indies ; 47 fathoms. 



Ophiopsila. 



Ophiopsila, Fbs., Trans. Linn. Soc, vol. xix., 1842. 



Disk covered with very minute, overlapping, smooth scales, which nearly or cmite cover 

 the narrow radial shields. Teeth. Tooth papillae sometimes present and sometimes 

 wanting. A few (six to eight) side mouth papfllee. Arm spines short, flattened, numerous 

 (six to twelve). Lowest tentacle scale very long, like a spatula, or a dagger. Lower arm 

 plates faintly indicated and sunken, making a groove in which lie the long tentacle scales. 

 Two genital openings in each interbrachial space, beginning outside the mouth shields. 



The disk is enclosed by extremely fine and even imbricated scales, which more or less 

 spread over the upper surface of the stout narrow, curved and bar-like radial shields, to 

 which are jointed the cylindroid heads of the genital plates. These become flat, at about 

 one-third of their length, and have there attached a flat genital scale, which is prolonged 

 quite to the radial shields by a slender additional piece. The arm bones, not unlike 

 those of Amphiura in outline, differ from allied genera by the massive shoulder in the 

 outer surface (PI. XL. fig. 2), which forms the hollow to receive the umbo of the pre- 

 ceding bone. The mouth frames are small, simple and without deep grooves, and have 

 a small linear peristomial plate, in one or two pieces. Instead of a jaw plate soldered 

 with the jaws, as in most Amphiurce, there is here a distinct plate, thick and very wide, 

 which bears large oblong teeth. 



See Plate XL. figs. 1-3. 



