REPORT OX THE OPHIUROIDEA. 159 



thicker than ia Amphiura, and have no upper outward projection. Their under surface 

 has a very krge canal (fig. b, t), but not so high nor so wide as in HeniiphoUs. 

 See Plate XL. figs. 4-7. 



Species of Ophiojjhragmus not herein described. 



Ophiophragmus ivurdemani, Lym. (PL XL. figs. 4-7). 



OphiopliixKjmus Wttrdemani, Lym, lU. Cat. ]\Ius. Conip., Zool., No. i. p. 132, 1865. 

 Amphiura WunJemani, Lym., Proo. Bost. Soc. Nat. Hist., vol. vii. p. 169, 1860. 



West Coast of Florida. 



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



AmpMura marcjinata, Orst. & Ltk., Vid. Medclel., Marcli 1856, p. 26 ; Addit. ad Hist., part 2, 

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



West Coast of Central America. 



Opjhiophragmus septus, Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 12, 18G5. 



Ampiliiura septa Ltk., Addit. ad Hist., part 2, p. 120, 1859. 

 West Indies ; 47 fathoms. 



Ophiopsila. 



Opliiopsila, Fbs., Trans. Linn. Soc, vol. .\ix., 1842. 



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

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

 wanting. A few (six to eight) side mouth papillae. 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 prolono-ed 

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

 those of AmpMura in outline, difi"er from allied genera l^y the massive shoulder in the 

 outer surface (PL 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 AmphiurcB, there is here a distinct plate, thick and very wide, 

 which bears large oblong teeth. 



See Plate XL. figs. 1-3. 



