10 B. W. PRIEST ON THB BBXAOTIFELLIIXJE. 



in this order are, anchor themselves by means of delicate glassy Ali- 

 ments, like fine white hair or spun glass, which in case of the 

 Hyalonema, or Glass rope Sponge, sends down through the soft 

 mud a coiled wisp of strong spicules, each spicule about as thick as 

 a moderate sized needle, which opens out into a brush, and fixes 

 the sponge in its place. The ends of these spicules are supplied 

 with an anchorate or grapnel form of termination. 



In the case of Euplectella aspergiilum, the late Sir Wyville 

 Thompson tells us that this sponge is imbedded up to its fretted lid 

 in the grey mud of the seas of the Phillippines. 



In a short paper, as the present one must be, I can only just 

 touch on one or two of the sponges contained in the first two 

 families of this order, hoping at some future time to bring others 

 before your notice. 



First, then, taking an example of a sponge held together by 

 silicified fibre, we have Euplectella aspergiilum, Euplectella being 

 derived from two Greek words signifying " well- woven." 



Most of you are familiar with the cornucopia-shaped sponge, that 

 at first sight can hardly be imagined to have been formed by any 

 member or aggregation of members so low in the Animal Kingdom, 

 but so it is, and the structure being so intricate, I shall take my de» 

 scription from Mr. Carter. 



" It has its spicular basket-work, both of the body and lid, 

 throughout, cemented together by an envelope of vitreous, ladder- 

 like fibre, which ladder-like fibre in a horny state is also a pecu- 

 liarity of some of the Keratose sponges. The main lines of spicules 

 are longitudinal and transverse, so that cutting each other at right 

 angles and at nearly equal distances, they leave a number of 

 squarish areas in the intervals, occupied alternately by round holes 

 and matted basket-work. Through this arrangement the squares 

 with holes and basket-work respectively form diagonal lines, again 

 crossing each other, but now obliquely and somewhat spirally round 

 the body ; while a number of compressed ridges or frills, about a 

 quarter of an inch high, formed of the same kind of vitreous 

 spicular structure as the rest of the sponge, run along in more or 

 less continuous spiral lines, obliquely through the squares of matted 

 basket-work, leaving those with holes free between them, finally ter- 

 minating above in a line which encircles the lid-like end, where the 

 latter is joined to the body. The lower end, on the other hand, 

 which is also closed, but of a conical form, similar to the end of a 



