HISTORICAL SKETCH. 



The species of Ophiuran,Ophiura brevispina ,the 

 life history of which is the subject of this disserta- 

 tion , was first discovered and described by Thomas 

 Say in 1325. (//•) 



Since this tine the species has been rediscover- 

 ed and renamed as many as three tines. It is probabiy 

 best known at &%e present fr iing - by one of its synonyms, 

 Ophiura olivacea , which was given to it in 13C5 by 

 Theodore Lyman (f.) . In his earlier work LYMAN distin- 

 guished 0. olivacea and O.brevispina but in his Chal- 

 lenger report on the Ophiuridae and Astrophytidae ($) . 

 he places the two species together as one under its 

 earlier name e ich, although less descriptive of. .the 

 species than that given by LYMAN, it is probably best 

 to retain. 



In 1352 1 AYERS described the species under the 

 name Ophiodema olivaceum in Vol. IV. of the Proc.Bost. 

 Soc .Nat .Hist . 



LUTKEN also described it as Ophiodema serpens 

 in 135G. 



