BY E. F. MALLMANN. 393 



loug projecting styli. But, in Uaspaxilla^ it is these long styli 

 also which are the coring spicules of the fibres, both axial and 

 extra-axial (the only spicules projecting therefrom being the 

 acanthostyli), whilst spicules corresponding to the small intra- 

 fibral styli of Echinaxia are wanting; and, furthermore, there 

 are present in Raspaxilla special dermal styli, disposed as in the 

 genus Raspailia. On the reasonable assumption of a near re- 

 lationship between the genera Echinaxia and Raspaxilla, it 

 accordingly appears probable that the long smooth styli of the 

 former are homologous with those coring the fibres of the latter, 

 and hence, almost certainly, with the principal megascleres of 

 normal Myxillinse. 



Under the name of Axinella niariaiia, Ridley and Dendy* 

 have described a species, of ramose habit, with a skeleton con- 

 sisting axially of " a fairly dense core of irregularly arranged, 

 short, bent, stylote spicules," and extra axially of very large styli 

 or tylostyli (up to 2200 by 30/u, in size) having their bases im- 

 bedded in the confused central mass and their apices projecting 

 far beyond the surface of the sponge. Only these two forms of 

 spicules are present. The short styli (size about 300 by 13/x, but 

 variable) are sharply bent near the base, finely and gradually 

 pointed at the apex, and rarely slightly spined. It is probable, 

 therefore, that this species is closely related to Echinaxia; 

 though the differences distinguishing it therefrom appear too 

 considerable to be regarded as of less than generic value. As 

 the species certainly cannot be permitted to remain in the genus 

 Axinella, nor yet in the genus Syringella, to which Topsent(9b) 

 would assign it, I propose for its reception the new genus 

 Axinectya. 



Another species possessing acanthostyli similar to those of 

 Echinaxia is that which 'J"hiele(5) has described as Maspailia{1) 

 villosa. This species, however, is of massive habit, without an 



* Report on the Monaxoiiida collected by H.M.S. "Challenger." In the 

 same report, there is also assigned to the genus Axinella a second species 

 with acanthostyli, viz , A . monticidaris. There can scarcely be any doubt 

 that the correct position of this species is in the genus Anlo.'<pongus 

 Norman, hitherto regarded as being represented only by the single species, 

 A. tabalatus Bowerbank. 



