Venus 3 Flower-baslcet. 



163 



while from near the base to the top, elegant frills or furbe- 

 lows rise at their intervals, composed of interlacing fibres. 

 These frills rise gently from the general surface, and stand 

 out from it to a distance of from one to three-eighths of an 

 inch. They have a general disposition to form diagonals to 

 the square meshes, which they cross in graceful undulations. 

 They are wider at the base than at the top, and no doubt 

 materially strengthen the delicate structure which they adorn. 

 In the writer's specimen they are in two sets, one at right 

 angles to the other, and must be regarded as beautiful instances 

 of decoration, arising out of a construction evidently intended 

 for the useful purpose of increasing the resisting power of an 

 extremely light framework. 



The first aspect of the Euplectella, under low magnification, 

 leads to the notion that the vertical and horizontal bundles of 

 silicious threads are simple cylinders, more or less closely 

 packed together ; but a closer investigation shows that they 

 are more complex. It is common to find two or more, as it 

 were, soldered together, and the external ones, especially, 

 frequently throw out branches and prolongations, which 

 form junctions with other threads far and near. These 

 junctions are sometimes smooth, and at others marked by 

 slight rounded prominences. A thread will often proceed for 

 some distance as a simple cylinder, and then divide, either 

 with a bold furcation, or forming two nearly parallel threads, 

 joined at intervals by cross pieces. Many instances may be 

 observed of little projections from such threads looking at each 



Fia. 1. — Portion of Network of Skeleton of JEuplectella speciosa, magnified. 



other across the narrow gulf, but not quite meeting, as if their 

 growth were arrested or incomplete. The threads that take 



