BY E. F. HALLMANN. 353 



curvature is slight, and the proportion of straight to curved 

 spicules about equal ; but, at times, most of the spicules are 

 curved, and some of them much curved. Their maximum size 

 varies in different specimens, from 286 by 6 /x to 305 by 9 fi; 

 while the shortest spicules in any given specimen arc of be- 

 tween one-half and two-thirds the length of the longest. 

 Loc. — Port Jackson. 



Stylotklla polymastia. (Text-fig.7). 



Introductory. — The species is represented in the collection 

 of the Australian Museum apparently only by a tiny frag- 

 ment, labelled ''Truncatella jyolymastia," received from the 

 British Museum. Judged by its spiculation, the fragment is 

 undoubtedly a genuine example of the species, but unfortu- 

 nately it is so small, that scarcely any information is obtain- 

 able from it concerning other characters. Nevertheless, it 

 enables one to say that the species is certainly not assignable 

 t^ the genus Stijlotella as defined above, but, in all probabi- 

 lity, belongs to CiocalyjMa — under which genus I propose to 

 bring it. 



In connection with the figure which appears in the Cata- 

 logue (Pl.iv., fig.i.) in representation of this species, a serious 

 error has been made. As I already have had occasion to men- 

 tion, the actual specimen, from which this figure was taken, 

 is still in existence (labelled in Lendenf eld's handwriting Side- 

 rodcrma navicelligerum R.&D.), and belongs to a hitherto un- 

 known species of Histoderma, described, in the Appendix 

 hereto, as //. actimoides. One can see, on comparing the 

 figure in question with Lendenf eld's description of Stylofella 

 polyniasfia, that the two are not compatible, although show- 

 ing in some respects an apparent agreement. 



In order to make the following description of the sj)ecics as 

 complete as possible, I have repeated Lendenf eld's description 

 of its external features ; but it should be borne in mind that, 

 possibly, this description is not applicable. In consequence of 

 the small size of the fragment, I have not succeeded in secur- 

 ing sections cut in the proper direction to enable me to deter- 



