16 Mindeskrift for J. Steenstrup. X. 



Locality. San Bernardino Strait, Philippine Islands (12° 27' N. 124° 3' E., 50— 100 

 fathoms ; bottom temperature 61° F.). Found among sponges. ^g 1911- Captain 



E. SUENSON. 



This species differs conspicuously from the other species of Ophiothela hitherto 

 describcd (whether they should all be united into one species, as suggested by 

 DoDERLEiN and KoEHLER, or not) in having only 5 arms and showing no trace of 

 sclfdivision, the other species having 6 arms and being selfdividing. 



ADDITIONAL NOTE 



After this paper had been sent to print, I had the opportunity, during a short 

 visit to London, of seeing in the British Museum some specimens (8) of Ophioteresis 

 elegans from the Seychelles („Alert"). I found them to vary very considerably in 

 the appearance of the ventral side of the vertebræ, so that it is impossible to 

 distinguish between O. elegans and tigris by means of this character. Also the side 

 arm-plates may be as broad as in the type of O. tigris. There is then not a single 

 character by which O. elegans may be distinguished from O. tigris, and accordingly 

 Bell's Ophioteresis elegans is synonymous with Lyman's Ophiothela tigris. 



Some time afterwards I called on Dr. D. C. McIntosh in Edinburgh, and by a 

 most fortunate coincidence I found him examining some Ophiurids from the Coast 

 of Portuguese East Africa, among which were several specimens af Ophioteresis. Dr. 

 McIntosh very kindly allowed me to dissect one of these specimens, so that I can 

 now also give some information of the anatomy of the disk of this Ophiurid. Un- 

 fortunately the specimen evidently had been nearly dry, so that it was impossible to 

 trace the shape of such delicate organs as the bursæ and the Polian vesicles. But 

 the structure of the genital organs could be made out. There is a large, compound 

 gonad at each side of the bursa and one at the outer end of the bursal slit. The 

 latter gonad is distinctly fanshaped, overlapping in the median line the correspond- 

 ing gonad of the other bursa in the same interradial space. This structure and 

 arrangement of the gonads is essentially the same as occurs in Ophiothrix, the main 

 difference being that in the latter there are generally two, sometimes three gonads 

 on the adradial side of the bursa. 



