SPONGES. 3 1 7 



not in abundance, may be seen ; Saxicavce push their 

 crimson siphons through, here and there ; Botrylli are 

 spread in patches, and Amcercecia are suspended like a 

 plentiful crop of tempting strawberries ; but Sponges 

 constitute the staple of the crop ; it is a veritable field 

 of Sponge. 



I have on other occasions described some of the more 

 characteristic phenomena of this class of creatures ; 

 the volcanic eruptions of the Crumb -of- bread Sponge, 

 the hills and poles and webs of the Kosy Crumb, the 

 protrusile bladders of the Sanguine, the starry spicula 

 of the Flat- Sack. 1 These I shall assume as known, and 

 shall confine myself to the enumeration and description 

 of a few other species which are found congregated on 

 this rocky roof. 



One of the first to catch the eye, by its gorgeous 

 colour, is a rather thin, soft, spreading patch, of the 

 richest vermilion hue. 2 It is of close substance, the 

 surface covered with shallow irregular sinuous channels 

 and minute orifices. It rarely exceeds an inch in 

 diameter, but throws out slender clinging processes 

 to some length. The flesh is dense. Under the mi- 

 croscope it contains three-rayed spicula, which are for 



i Tenby. The systematic appellations of these four species are Hali- 

 chondria panicea, Halichondria rosea, Halichondria sanguined, and Grantia 

 compressa. 



8 Grantia coriacea. 



