HIPPOTHOA. 293 



2. HiPPOTHOA DiVAEiCATAj Miss ElUott. (Plate XV. 

 fig. 55.) 



Hab. On old shells^ especially bivalves^ from deep water. 

 On oyster-shells; Sidmouth^ Mrs. Gatty ; onJPimia, from the 

 island of Coll, D. L. ; on difl'erent kinds of algse, coast of 

 Ayrshire, D. L. 



This is so delicate and slender that it requires good 

 eyes to observe it ; and when it is old and opake, and on a 

 whitish shell, an unpractised eye, even when aided by a 

 lens, woidd scarcely succeed in detecting it. When young 

 and fresh it has a crystalline appearance; the cells, which 

 are connected by a dehcate calcareous thread, are more 

 distant from each other than those of H. catenularia. Dr. 

 Johnston mentions that there is " a variety of H, divaricata 

 in which the cells are contiguous. It is found on seaweeds 

 only, so far as my experience goes." This accords with my 

 own experience in so far that I have seen on seaweeds the 

 pretty Httle variety with a very short thread betwixt the 

 cells ; yet the very last specimen of H. divaricata which I 

 fell in with was on Delesseria sinuosa, as transparent almost 

 as dew, while the portion of thread which connected the 

 sparkling bugles was fully as long as I had ever seen it 

 upon shells. 



