164 Mr. H. J. Carter on Parasites of the Spojigida. 



tioned, but extends outwards laterally for some distance over 

 the ecliinating spicules of which they are respectively chiefly 

 composed, finally ending on the surface in a clathrate struc- 

 ture, which throws out small, irregular, wart-like, botryoidal 

 masses of a black-brown colour (in sizes below l-36th inch 

 in diameter). The latter are composed of a crust formed of 

 radiating columns of brown cells in juxtaposition (each column 

 consisting of a transparent theca enclosing about a dozen) , con- 

 taining, or accompanied by, or both, globular tufts of branched 

 short filaments of rcf/ cells mixed with paraphyses, the filaments 

 being clavate from the enlargement of the cells towards the 

 free ends, thus becoming terminally (?) sporiferous, much like 

 those of IIy])oglossum Woodwardii figured by Payer (Botan. 

 Cryptogamique, 1850, p. 47, fig. 209). No tetraspores could 

 be recognized ; but where the pseudofrondaceous layer had left 

 the sponge and spread itself over surrounding Balanus-^^^i 

 it presented somewhat the appearance of Hildenhrandtia san- 

 guinea. 



The red cells of the thallus are about l-4000th inch in 

 diameter, and the brown cells of the columns about a third 

 smaller, while the terminal cells of the branched filaments in 

 the " tufts " are the largest of all. The brown warty fructi- 

 fication (? nemathecia) is surrounded by a transparent mem- 

 branous envelope ; but this, as well as all the other structures 

 that I have mentioned, can only be seen under the micro- 

 scope in a fresh state, or on soaking in water, after having 

 become dry. The red colouring-matter of the cells is not 

 affected by drying, nor is it much altered by the addition of 

 liquor potassje. 



As this Alga appears to be unnamed and undescribed, this 

 can be best done by those who have given their attention 

 especially to the subject. 



OsciJlatoria. 



There is a Suberite with pin-like spicule only (that is, 

 without flesh-spicule), which occurs on the rocks here a little 

 above low-water mark, in small thin patches about half an 

 inch in diameter, of a beautiful cobalt-blue colour; and when 

 examined with a microscope the blue colour is found to be 

 owing to the presence of innumerable short separate filaments 

 of an Oscillatorian alga, which, answering to the description 

 of the genus Hypheothrix^ Kg-? ^'^^ with blue granules, from 

 which the cobalt-blue colour of the sponge is derived, might 

 be called "i/. ca^rwiea." The filaments vary in length under 

 l-1500th inch, with a diameter of l-12000th inch ; and the 



