342 THE SPOXGIDA OR PORIFERA. 



With this arrangement we have seen easily (working by day-light) 

 the flagella, collars, neuclei, and neucleoli of the collared cells of 

 Sycafidra ciliata. 



We have before us five specimens of British Spongida (Plate 

 XIV.), all of which are interesting to us, some from personal associa- 

 tions, others as representing species of which noteworthy observa- 

 tions were made by distinguished biologists who have passed away, 

 as Grant and Bowerbank, etc. The two specimens (Figs, i and 2, 

 Plate XIV.) of the Crumb-of-Bread '^^or\g^ {Haiicho?idria panicea) 

 are very different in general form on account of the different points 

 of attachment from which they grew. The first specimen (Fig. i) 

 was scraped off a rock, and is of a flat shape, except for the pro- 

 jecting conical or teat-like eminences, fourteen in number, which 

 jut out abruptly, some to the extent of half-an-inch, from the flat 

 roughly-porous sponge mass. At the free end of each of these 

 projections is a round or oval orifice (^, a^ a) — the termination of 

 a canal leading from the sponge. These apertures averaged about 

 one eighth of an inch in diameter, some being larger, others rather 

 less, and are termed the oscttla or /cecal orifices of the Sponge. The 

 Sponge as a whole is of a light grey-brown tint, of an exceedingly 

 open and porous texture, and measures about one and three- 

 quarter inches across, from two to three inches in height (one 

 border being shorter than the other), yet only averages a quarter 

 of an inch in thickness between the conical prominences. The 

 entire thickness of the Sponge, if we include the largest cone-like 

 projections (that is, measuring through the Sponge from its base of 

 attachment to the rock to the most prominent osculum), does not 

 exceed three-quarters of an inch. The hinder surface of the 

 Sponge, which has been torn off the rock, is flat and porous, with 

 many fragments of acorn shells embedded in its substance. 



Our other specimens of H. patiicea (Fig. 2, Plate XIV.) pre- 

 sents a very different appearance, and it is of interest to us since 

 it was the first living sponge we witnessed in a state of activity, 

 and discharging, for several hours continuously, strong currents from 

 the oscular orifices. The following observations were made 

 regarding this identical specimen in another paper (published in 

 the Field Club, July, 1892) : — 



