164 



OPHIOTHRIX VIOLACEA. 



else dull green or blue. The young, with a disk of S'"™,, have arms 

 2gmm. -j^ length ; the disk is already closely covered with small spines, 

 each bearing a crown of three long, sharp thorns ; the arm-plates are 

 proportionately longer than in the adult, and the arm-spines have rather 

 lono-er thorns. Very often the adult has only spines of the smaller sort 

 on the disk. Some specimens have the disk as large as 7°""'. 



0. cmrjidafa bears some resemblance to 0. violacea ; the latter, how- 

 ever, has not banded arms, and has no such variety of coloration when 

 living ; moreover, 0. angidata is smaller, has under arm-plates pro- 

 portionately longer, arm-spines commonly more numerous, and about 

 eighteen tooth-papilla?, while 0. violacea has as many as thirty. It 

 differs from O. spkulata and 0. diimosa in fewer tooth-papilla?, shorter 

 arm-spines, and in being a smaller species. 



LIST OF SPECIMENS. 



Catalogue 

 Number. 



132 

 133 

 134 

 135 

 300 



982 



Original Number 

 Number, of Spec. 



Locality. 



When 



Collected. 



Whence obtained. 



12+ 



12-h 



12-h 



1 



12-f- 



Museum of Comparative Zoology. 



Cliarleston, S. C. 

 Charleston, S. C. ? 

 Charleston, S. C. 

 Waccamaw, S. C. 

 North Carolina. 



1851. 



1852. 

 1853. 



Prof. Ajiassiz. 



Prof. Agassi z. 

 Prof. Agassiz. 



Smithsonian Institution. 

 South Carolina. | 



]\Ir. Kurtz. 



Nature of 

 Specimen. 



Alcoholic. 



Alcoholic. 



Ophiothrix violacea Mull. & Trosch. 



Stella marina minor echinata purpurea? Sloane. Yoy. to Jamaica, p. 272, pi. 244, f. 8, 9. 1725. 

 Stella scolopexdkoides ; Jamaicens'is purpurea? Linck. De Stel. Mar., p. 51. 1733. 

 Ophiothrix violacea Mull. & Trosch. Syst. Asterid., p. 115. 1842. 

 Ophiothrix carib'xa Lutken. Vidensk. Meddelelser. Jan., 1856. 

 Ophiothrix Kroijeri Lutken. Vidensk. Meddelelser. Jan., 185G. 

 Ophiothrix violacea Lutken. Addit. ad Hist. Oph., p. 150 1859. 



Special Marks. — Dark-purpUsh blue, with a white line along the 

 arm. Small, forked spines on the disk, with a few long ones. 



Bescrij^tion of a Specimen. — Diameter of disk, 10""" ; from outer 

 side of mouth-shield to outer corner of opposite mouth-slit, 4™'"- ; width 

 of arm without spines, 2.3"""- ; length of arm, 62'"'"- ; distance from outer 

 side of mouth-shield to inner points of tooth-papilla?, to that between 

 outer corners of mouth-slits, 2 : 1.7. Tooth-papilla? arranged in an oval 



