W. LEUCKARTI. — GEX. CHAEACTEKS. 285 



The branches emanating from the stem may be simple and 

 unbranched, in which state they may sometimes attain a length 

 of 40 mm ; but more usually are they provided with secondary 

 branches, developed in mimlier and length proportionally to the 

 primary branch, which, when large, may bear even tertiary 

 branchlets on its secondaries. The secondaries and tertiaries 

 shoot out more or less inclined towards the apex of the branches 

 bearing them, frequently forming with the latter an angle of 

 about 45°. 



On the lower portion ol' the stem, the branches are obliterated 

 and are represented by compact stumps. The longer stumps 

 may be frayed out at the outer end into a tuft of separate 

 needles. Such remnants of the branches are sometimes found 

 even on the basal disc. Complete branches begin to exist at 

 some distance from the basal end. They are at first all small. 

 Larger and more complex branches add themselves to the smaller, 

 in a generally gradual development, towards the middle of the 

 stem. Thence towards the upper end the branches again become 

 continually shorter, and finally they become so very short that 

 the general form of the sponge gradually narrows towards, and 

 is pointed at, the apex (PI. XII, iig. 3). In a very large specimen 

 (855 mm. high), one of the largest branches was 200 mm. long, 

 bearing numerous secondary branches up to 55 mm. in length. 



I have said the branches arise on all sides of the stem ; but 

 it must not be supposed that they are equally developed in all 

 directions. As a constant feature seems to be the situation of the 

 larger branches oppositely along two sides of the stem. As the 

 result of this arrangement the entire sponge is of a more or less 

 flattened form: it is laterally compressed, if one may so express 

 it. It is also distinctly noticeable that the secondary branches 



