K-^'^-^ 



THE OPHIURIDiE 



129 



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Color in alcohol : gray. 



Five specimens from Stations 3411, 1189 f. ; 3413, 360 f. 



- 1- 



This species stands very near to Ojjliioglfjplia inornata Lym., the only dif- 

 ference of any importance, as far as we are able to see, being that the 

 dorsal plates are here not divided by a longitudinal median line. In every 

 other respect the two species seem to be quite alike. Lyman does not 

 mention that the mouth shield in 0. inornata is divided by a longitudinal 

 median line, but the figure shows that line very clearly. 0. inornata was 

 taken in the Atlantic in 1° iT Lat. N., 24° 26' Long. W. (1850 f.). 



r 



On Station 3400 was taken a young Ophiuran (diameter of disk 4 mm.), 

 which we must regard as the young of 0, divisa, though it differs somewhat 

 from the above described larger specimens. Four of the mouth shields are 

 undivided, but the fifth is divided as on Plate IV. Fig. 10;* but especially 

 the covering of the dorsal side of the disk is different, the six primary 

 plates being very large, polygonal, taking up by far the most space. At the 

 marn-in of the disk are seen the short, broad, polygonal, not separated radial 

 shields and two smaller plates in each interbrachial space. No genital 

 papillae or arm-comb yet developed. The dorsal plates as yet only partly 

 divided by a median line^ but on some few of them this line is distinct. 

 There are only one or two arm-spines below and one at the upper side of the , 

 arm. Mouth papillae and tentacle scales as on the larger specimens; nor do 

 the ventral plates show any noteworthy difference. (Plate V. Fig. 2.) 



The eif^-ht species here described included, there are now know^n no less 

 then eighty-seven species of the genus OpJdoglypha, Evidently the genus 

 needs to be subdivided; but it seems impossible to do so without having 

 specimens, or at least good figures, of all the species. Meantime very 

 much is still wanting in this respect, several of the species having never 

 been figured. Some species, however, show more or less important charac- 

 ters in common, and such will possibly form definite groups or subgenera. 

 Lyman established three groups with the types 0. ciliaia Eetz., 0. hillata 

 Wyv. Thoms., and 0. 7iodosa Ltk., but for many species he did not find any 

 common character of importance. Ludwig (72) proposes to make a sepa- 

 rate genus of those species which have no arm-comb, Ophioglyphina. We do 

 not believe this character to be of so great value, as these species are 



* Sometimes also an undivided moutli sliield may bo found in larger specimens. , 



