332 



DISCOVERY REPORTS 



the fact that they were found at opposite sides of the Atlantic. The skeleton in the 

 present specimen consists of loose bundles of styli running from the substratum to the 

 surface (Fig. 29). 



Distribution. West Indies. 



Genus Plicatellopsis, gen.n. 

 Genotype. P. arborescetts , sp.n. 



Diagnosis. Axinellidae with main skeleton a confused or regular reticulation of styli 

 or tylostyli from which ascending fibres pass outwards to dermis; dermal skeleton in 

 form of bundles of small styli or tylostyli; interstitial spicules, when present, long 

 slender tylostyli. 



Remarks. The genus includes, in addition to the genotype, P. flabellata, sp.n. and 

 PlicateUa expama, Thiele. The use of Schmidt's genus Plicatella (1870, p. 45 : genotype, 

 Reniera labyriiithka, Schmidt, 1864, p. 39, pi. iv, fig. 9) by Thiele is unjustified, since 

 the only information we have is that the skeleton contains styli only. We know nothing 

 of the arrangement of these styli, and it is probable that Plicatella is more closely 

 related to Stylohalina than to any other genus. At the same time, there is a close relation 

 between Plicatella and Plicatellopsis; but until the type of the former is redescribed 

 it will be impossible to define it. 



b . . . ^ . 



Fig. 36. Showing arrangement of skeleton in a, Plicatellopsis expansa (Tliiele), 

 b, P. arborescens, sp.n., c, P. flabellata, sp.n. 



