CAULOPHACID^. 81 



i^ow, as regards Asconema (with the single species, A. seiii- 

 balense), the unpaired ray of its pentactinic dermalia and gastralia 

 is, to judge from F. E. Schulze's description and figure (Chall. 

 Eep., p. 117 ; PL XXI., fig. 4), scarcely differentiated in appear- 

 ance from the para tangential rays. It is exceedingly doubtful if 

 it can at all be called pinular. The mere fact that the unpaired 

 ray in those pentactins projects freely outwards and does not dip 

 into the body-wall, appears to me a much too slight and unreliable 

 ground for excluding the genus from the Rossellidœ. This I say, 

 not only on a general consideration of the wide variability — ranging 

 from hexactins down to diactins or even to monactins — exhibited 

 by dermalia in that family, but also in view of the fact that in 

 Lophocalyx spinosa F. E. Sch. ('oo, p. 37) we have a Kossellid 

 in which there occui-, together with stauractinic dermalia, others 

 that are pentactinic and have the unpaired ray directed outwards. 

 I consider the dermalia of Asconema to have been directly 

 derived, by atroph}^ of the proximal ray, fiom such simple 

 hexactinic forms as are sometimes shown by certain Rossellids, — 

 not from such hexactinic pinules as are possessed by Caulophacus, 

 as the pentactinic pinules of Sympogella mix unquestionably are. 

 The same should hold good mutatis mutandis for the gastralia 

 also. Exceptional as the condition certainly is, the pentactinic 

 dermalia and gastralia with the unpaired simple ray directed 

 away from the body are, in my estimation of their bearing 

 on the systematic, no farther removed from the original simple 

 hexactinic form than are those — so commonly met with in the 

 Rossellidaä — in which the unpaired ray is directed the other 

 way. After all, I think that, if Asconema is to be kept separate 

 from the Eossellid?e, it should rather be removed from association 

 in the same family with Caulophacus and Sympagella. 



