258 



29 millim., and arms of 100 millim. The smallest had a disc of 

 14 millim., and arms of 35 millim. ; there were 7 or 8 arm- 

 spines ; most of the upper arm-plates were broken in only two 

 pieces ; the color was very dark umber, with fine, sinuous, black 

 lines on the disc. 



Ophiura brevispina (Say) is unquestionably a true Ophiura. 

 According to the original description, it must be a brittle-star 

 without radial shields, (this excludes 0. cinerea, 0. rubicunda, 

 and 0. squamosissima ;) with arm-spines of equal length, (which 

 throws out 0. elaps ;) with undivided upper arm-plates, (it cannot 

 then be 0. guttata ;) with only 7 arm-spines, and the sides of the 

 disc " concavely arched," (which eliminates 0. brevicauda ;) there 

 remains therefore only Ophioderma (^Ophiura) serpens, (Ltk.) 

 which agrees well with Say's description, and is found abundantly 

 in Florida. In future, therefore, Ophioderma serpetis, (Ltk.) 

 must fall among the synonymes of Ophiura brevispina, (Say.) It 

 is satisfactory to know that all of Say's Ophiuridce have now been 

 identified. They stand thus : — 



say's names. present names. 



Ophiura angulata, (Say.) Ophiothrix angulata, (Ayres.) 



Ophiura elongata, (Say.) Amphiura cordifera, (Lyman.) 



Ophiura crassispina, (Say.) Ophiocoma crassispina, (Ltk.) 



Ophiura reticulata, (Say.) Ophionereis reticulata, (Ltk.) 



Ophiura brevispina, (Say.) Ophiura brevispina, (Say.) 



Ophiura appressa, (Say.) Ophiura appressa, (Say.) 



Ophiura paucispina, (Say.) Ophiolepis paucispina, (Ltk.) 



Ophiura isocantha, (Say.) Ophiostigma isocantha, (Ltk.) 



Ophiura flaccida, (Say.) Ophiomyxa fiaccida, (Ltk.) 



Ophiura cirrosa, (Say.) Asterochema oligactes, (Orsted.) 



Dr. LiJtken agrees with me in my identification of Asterias cor- 

 difera (Bosc,) (see page 203,) and wishes to change the name 

 Amphiura cordifera (Ltk.) to Amphiura Riisei, (Ltk.) 



Ophionereis, (Liitken.) 

 Ophionereis Xantusii, (Lyman,) sp. no v. 

 Description of q, Specimen. Diameter of disc, 7.7 millim. 



