238 RECENT OPHIURANS. 



577. H. GRACILIS Verrill, 1867. Trans. Conn, acad., 1, p. 262. Plate 9, f. 7, f 



1 coTYPE. Panama: Pearl Islands, 4-6 fms. 



Ophiophragmus. 



Lyman, 1S65. lUus. cat. M. C. Z., no. 1, p. 12, 131. 



Type-species: Amphiwa wurdetnanii Lyman, 1860. Proc. Boston soc. nat. hist., 7, p. 196. Tjrpe here 

 first definitely designated. 



578. 0. BRACHYACTIS, sp. nov. (Ppaxiis, short + UtU, ray). Plate 10, f. 13, 14. 



Disk 7 mm. in diameter; arms less than 30 mm. long (hence the name). 

 Disk covered with a coat of coarse scales, about 8 series from center to margin 

 and about 6 series across an interradial area; the six primary plates form a 

 compact group at center; around the margin of the disk, interrupted only where 

 the genital plates join the radial shields, is a close-set series of low, blunt cyhtidri- 

 cal spinelets. Radial shields in close contact, about 1.5 mm. long by 1 mm. wide, 

 broadest distally. Upper arm-plates broadly in contact throughout, very short, 

 the width equaUing three times the length or more; they are often broken in two. 

 Interbrachial spaces below covered by a dense coat of rather coarse scales. 

 Oral shields very small, diamond-shaped with rounded angles, rather longer than 

 wide. Adoral plates relatively large, 4- or 5-sided, meeting broadly within. 

 Oral papillae, 3 on each side of the jaw, the innermost thick and Amphiura-like, 

 the others scale-like and subequal. First under arm-plate large, equal to the 

 adoral plates and completely separating them; succeeding plates wider than 

 long, or square, broadly in contact throughout. Side arm-plates low and incon- 

 spicuous; each carries a series of three short, 4;hick, blunt, subequal (or uppermost 

 smallest) spines about as long as the arm-joint or a little longer. Tentacle- 

 scales two, one on the side arm-plate and one on the under arm-plate, except 

 on the first arm-pore where there is no scale on the side arm-plate. Color 

 (dried from alcohol), whitish; the arms show faint indications of having been 

 banded. 



HoLOTYPE (M. C. Z. 1120). Florida: off Sombrero Key, 47 fms., April 

 2, 1872. Wm. Stimpson coll. 



With tliis specimen, Mr. Lyman has the note: "sp. nov. near Wurdemani 

 Scaling flatter, coarser. Mouth different. Arms shorter?" None of our 

 specimens of wurdemanii show any approach to this specimen in either the 

 character of the disk-scahng or the length of the arms. It differs from septus 

 in the length of the arms and the number of tentacle-scales. It is very near 



