270 



Oxjjaster. Frequent; actiues loug. 



Spheraster. Frequent; much smaller tlian the oxyasters. 



Microxea. Not uncommon l)otli in the parenchyme and the 

 cortex ; around the stomas they are very abundant and , by pro- 

 jectiug partly into the luraen , make the stomas look irregulary 

 shaped if seeu with the naked eye. The ends are not sharply 

 poiuted; the surface is very little roughened and they are often 

 centrotylote. 



Found between Naples and Capri at about 200 meters. 



Penares helleri (O, S.) Gray. 



Syn. 1864 Stelletta helleri O. S. 

 1867 Penares helleri Gray. 

 ? 1868 Papyrula candidata O. S. 

 1888 Papyrula helleri Soll. 

 Cf. Schmidt, Suppl. Spong. Adriat. Meeres (1864) p. 32; PI. 

 III, fig. 8. 

 Schmidt, Spong. Kust. Algier (1868). p. 18—19; PI. IV, 



fig. 1. 

 Marenzeller in Anu. K.K. Naturhist. Hofmus. Bd. IV (1889) 

 p. 17; PI. m, fig. 7. 



I have demonstrated ^) that Schmidt's Stelletta helleri has to be 

 named Penares helleri ; so I need not explain this again. 



The shape of this sponge is elongated and spherical , broader at 

 the top. The surface is smooth but uneven; as a rule there is 

 but one wide proct. The stomas are scattered irregularly over 

 the surface. The size of my specimens was from 3 X 3.5 to 5X8 

 cm. in diameter. The colour is pale yellowish brown, somewhat 

 darker in the ueighbourhood of the proct. 



The parenchyme is yellowish , the thin cortex darker. In ac- 

 cordance to the wide proct is the ultimate excurrent canal also 

 rather wide; some maiu canals terminate herein. 



1) Notes on Some Species of Stelletta and other Genera allieJ to it. In: Tijdichr. 

 Nederl. Dierk. Ver. (2). III, Part. 1. 1890. 



