EEPORT ON THE OPHIUROIDEA. 



215 



Opldothrix magnifica stands near, having a long genital plate reaching nearly to the 

 mouth shield, and a hollow lozenge on top the first free arm bone ; the genital scale too is 

 extremely large and thick, and has a slightly lobed edge. The radial shields, however, 

 are smaller than usual, with crusty, rounded, not elongated, scales in the interbrachial 

 spaces. 



Ophiothrix suensonii, which leads a distinct group of Ophiothrices, presents some 

 variations in the skeleton. The radial shields are of great size, massive, and wdth smooth 

 edges, and the pairs are scarcely separated. The first free arm bone has a slight elon- 

 gation on its upj)er surface. The genital plate is flat and much thinner than in species 

 already treated. The upward forward apophysis of the arm bones is even longer than 

 usual, and of a somewhat different form. 



See Plate XL 1 1, fios. 5-8. 



Table of Species of Ophiothrix. 



" E ® g 



o 3 3 2 



rH P^ tl r« O 



S ci '^ o 



^ ° £/■§ 



<u ^ O p 



■-S n '-3 '^ 



.a 3 :3 M :2 



(fl O OJ > 



O d 





ca g « g » 



o S c3 M 



^ o > :r* 



^ o -*^ >■ ^ 



o 



L<arge (disk 16 mm.). Eadial shields somewhat sunk in) 

 swollen disk, "which hears various short stout stumps, ]> 

 mingled sometimes with a few slender long spines, . . j 



Oph ioth rix fragilis. 



Small (disk 11 mm.). Eadial shields somewhat sunk in) 



puffed disk, which is evenly beset with triiid stumps, '- Ophiothrix: echinata. 

 mingled with a few cylindrical spines, . . . j 



Similar to Ophiofhrix echinata.. but lowest arm spine as far 1 ,,,.,, . , 



inward as seventh joint is a doulilo or triple hook, -J •^ ^ '^i 



Large and similar to Ojihiothrix fraijilis, but mth short tliiii 

 arm spines, high arched arms, and minute spines on upper 

 arm plates, ....... 



Similar to Ophiothrix fragilia (same ?). Disk beset with ' 

 thorny grains, conical stumjss, and very stout, columnar 

 .spines, . . . . . . . \ 



Disk above closely set with grassy fluted spines, without 

 stumps. Eadial shields naked, except sometimes a few 

 minute spines, ...... 



Similar to Opihiothrix achinata (same?), but larger and disk 

 beset with stouter stumps, and spiines having crowns of 

 tkree to seven thorns, ..... 



Similar to Ojihiothrix pientaphylhim (same^), but only seven 

 arm spines, and mth a red spot on each upper arm plate, . 



Opihioth rix liitJceni. 



Ophiothrix pentaphylliim. 



> Ophiothrix alopecuriin. 



Ophiothrix lusitanica. 



Arms seven to ten times diameter of disk, 

 jointed on little mamelons. 



A few long disk spines which are 



1 



> Ophiotlirix mamdata. 



\ Ophiothrix quinquemaculata. 



Second and third arm spines largest and slightly club-ended. Disk set with j 

 short thorny cylinders. Eadial shields naked. Under arm plates trans- 

 verse oblong with rounded corners, . . . . . ) 



OpHiiothrix fumaria. 



