CKATEROMOKPHA MEYERT. 66 



The .«anie kind of spicules as the gastralia just mentioned, 

 are present on the surface of the excurrent canals, Tliese may 

 tlien 1)0 called the canalaria. They are most frequently met 

 with in the widened proximal region of the canals, directly ad- 

 joining the apertures into the gastral cavity. It may safely lie 

 concluded that the same kind of lining spicules, whatever he 

 their names, extends from the gastral cavity into the excurrent 

 canals, Followins; the latter distad towards and into their nar- 

 rower lu-anehes, the canalaria become more and more scarce until 

 they cease altogether to exist. 



To be explicit, the canalaria are, mostly at any rate, rough 

 pentactins with the unpaired ray directed distad. So far as those 

 in the body proper are concerned, I have not seen hexactinic 

 forms amongst them, luit I believe that some might possibly 

 have been discovered, had a more extensive search been made. 

 On the other hand, in preparations of tissues from the upper 

 part of the stalk, I find a considerable quantity of regular 

 hexactins occurring together with pentactins. All these spicules 

 are quite like the gastralia in appearance and without doul)t 

 represent the canalaria lining the excurrent passages in the region 

 mentioned. For Philippine specimens F, E. Schulze ('87, p. 

 16') ; '97) has given rough oxyhexactins as the canalaria gene- 

 rally. T find this fully borne out by the preparations of a Oebu 

 specimen at my disposal. Nevertheless, the difference here indi- 

 cated as regards canalaria I regard as probably inconstant and 

 therefore as being not of systematic importance. 



Of the hexasters, tlie oxyhexmier (PL IV., fig. o) occurs 

 abundantly in the clioanosome, ])iametei', 90-120 //. Each very 

 sliort princi])al bears usually 2-3, sometimes 4 and even 0, 



