MUSEUM OF COMrAUATlVE ZOOLOGY. 217 



OPHIURANS AND ASTROPHYTONS. 



OPHIURID^. 



Ophiopeza Petersi sp. nov. 



Plate II. FiRs. 32 - 24. 



Special Marks. — Radial shields naked. Mouth-shields wider than lonjj. 



Description of an Individiml. — Diameter of disk 9 mm. Length of arm 

 about 54 mm. Width close to disk, without spines, 1.8 mm. Mouth-papillae from 

 sixteen to eighteen to each angle, the three outer being wider and rounded ; 

 the next three or four tooth-like and sharply pointed ; the two at the apex 

 shorter with a rounded edge. Mouth-shields large, triangular, with a blunt 

 angle inward, and outer edge irregularly curved ; length to breadth 2 : 2.5 mm. 

 Side mouth-shields very small, triangular, occupying the lateral corners of the 

 mouth-shield. First under arm-plate small, broad hexagonal, with sharp angles 

 at the lateral corners ; the rest are about as long as wide, and rounded, with the 

 outer edges overlapping, and having re-entering curves on the lateral sides, 

 where are the tentacle-scales. Side arm-plates flat, meeting neither above nor 

 below, the entire length of the arm. Upper arm-plates slightly swollen, wider 

 without than within, having straight lateral sides and the outer side curved. 

 Radial shields small, widely separated, longer than broad ; length to breadth 

 1.5 : .7. The rest of the disk above and below, as also the space between the 

 mouth-shield and tooth-papilla;, is covered closely with fine grains, about eigh- 

 teen to the length of a mm. Five or six short, blunt, tapering arm-spines, evenly 

 spaced on the outer edge of side arm-plate ; the four uppermost about .7 mm. 

 long, the lowest 1 mm. Toward tip of arm there are only three s])ines. Two 

 flat rounded tentacle-scales to each pore, whereof the upper one covers the base 

 of the lowest arm-spine. Color in alcohol, pale yellow, 



Sigsbee, Lat. 22" 9' 15" N., Long. 82° 21' W., 177 fathoms, 3 specimens. 



0. Petersi difl'ers from 0. fallax in having naked radial-shields, a coarser 

 granulation, fewer arm-spines, and wider mouth-sliields ; and from 0. Yoldii 

 in having radial shields and the lowest arm-spine longest, while 0. Yoldii has 

 the middle one longest. The genus stands so close to Pectinura as scarcely 

 to be separable. 



Ophioglypha variabilis Lym. 



OpMoglypha variabilis, Bull. Mus. Conip. Zoi31. Vol. V. No. 7, p. 85, PI. III. Figs. 

 70, 78, 79. 1878. 



Station 16, 785 fathoms, 1 specimen (Var. ?). Station 29, 955 fathoms, 1 

 specimen. Station 41, 860 fathoms, 1 specimen. 



I am not able to certainly distinguish these specimens from those of the 

 " Challenger " brought from deep water near Amboyna. 



