Vierrill, Notes on Radio ta. 259 



are ovoid, the smallest end inward ; in 0. athiops they are oblong 

 with rounded corners. 



The color, both in alcohol and when dried, is a dark, rich brown or 

 almost black above, occasionally with distinct, broad bands of gray- 

 ish on the outer part of the arms. Sometimes the disk is blotched 

 with grayish white. Lower surface of arms and chewing apparatus 

 grayish brown, rest like upper surface. Young specimens are lighter 

 colored and more conspicuously banded. 



Ophiocoma Alexandri Ljoiian, op. cit., p. 74. 



Several specimens of this species were collected by Mr. Brad- 

 ley at the Pearl Islands, and a single, large one, at Panama. It occurs 

 at Acapulco (Miis. Comp. Zool.), and Cape St. Lucas (Smiths. Inst.). 



Our largest specimen has arms about 5*5 inches long ; disk '8 in di- 

 ameter. The color of the upper side, in alcohol, is yellowish brown on 

 the disk ; the arms a brighter shade of the same, with unequal trans- 

 verse bars of dark brown, the lighter colored plates finely mottled 

 with yellowish-white. Lower surface of arms light yellowish brown, 

 with a narrow longitudinal stripe of darker brown passing along each 

 side of the lower plates. Mouth-shields and other parts about the 

 mouth light brownish yellow. 



This species may readily be distinguished from the preceding by 

 its relatively longer and more slender arms ; by its brighter and 

 lighter colors, and pecculiar markings on the arms ; by its disk covered 

 with little spinose grains ; by the arm-spines arranged in rows of five 

 to seven, the third and fourth from the lowest being longest, the upper 

 one smallest ; by its nearly round mouth-shields, a little truncated 

 iuTvardly ; and by difierences in the form of the upper and lower 

 arm-plates. 



Ophionereis annulata Lyman, op. cit., p. 143. 



Ophiolepis annulata LeConte, Proc. Phil. Acad., v, p. 317, 1851. 

 0. triloha Liitken, Vidensk. Meddelelser, 1856. 

 Ophionereis triloba Liitken, Addit. hist. Oph., p. 112. 



This species is very common at Panama and the Pearl Islands, Mr. 

 Bradley having sent numerous specimens. It occurs, also, at Cape St. 

 Lucas (J. Xantus, Smithsonian Inst.) and on the west coast of Central 

 America, whence Dr. Lutken received his specimens. Mr. Bradley 

 collected, also, a few specimens at Acajutla, San Salvador. It lives 

 under stones and in crevices at and near low-water mark. 



Our largest specimens have arms 3-3 inches long, the disk -5 broad. 



It may be recognized by its long, slender arms, with three rows of 

 spines, of which the middle one is considerably longest. Disk covered 



