196 ART. 7. 1. IJIMA ; HEXACTINELLIDA, IV. 



but also ill the strikingly and deusoly hispid character of the 

 gastral surface (see Coutrib., III., PI. VI., fig. IJ). This is 

 caused by nuineious [)rojectiiig ueedles of a moderate strength, 

 occuring from the oscular edge downwards over the entire gastral 

 surface of the specimen. They are firmly implanted in the 

 sponge-wall, their inner ends protruding 5 mm. or more, sometimes 

 vertically but more usually inclined in indefinite directions. It is 

 entirely beyond question that the spiny character of the internal 

 surface is not accidental but natural. 



The spicules of this specimen will be specially dealt with 

 after 1 shall have described those of the type-specimen in the 

 following paragraph. 



Spiculation. 



First, that of the tyi)e specimen (PI. XIV.,, fig. 15). 



The principal parenchymalia are oxydiactins which may attain 

 a length of 9 mm. and a breadth of 250 /-« in the middle. They 

 are relatively thick, nearly straight but sometimes bow-like or 

 boomerang-like spicules ; entirely smooth and not very much 

 attenuated towards both sharply pointed ends. Small and finer 

 parenchymalia are of the usual characters. 



The needles projecting from the gastral side are oxydiactins 

 similar in appearance to the principal parenchymalia. They may 

 be 9 mm. long and 90 /^- thick. A varying number of fine coinital 

 diactins are found accompanying them. 



Hypodermal oxypentactim are mostly found seveial together 

 in loose groups, in which the smaller and therefore younger ones 

 are always more deeply situated than those of older formation. 



