BRITISH SPONGIAD/E. 35 



dried state. In both cases it was closely attached to and 

 coating the piece of rock on which it was seated. Mrs. 

 Backhand found it at Guernsey. On a small slip of paper 

 accompanying the specimen she has written : " What are 

 these Grantias, some are dark crimson when living on sponges 

 at low water?" Examined by the microscope in a little 

 water these specimens exhibit an abundance of red sarcode. 

 Dr. Johnston describes them as of a " dirty bluish gray or 

 white when recent." The specimens I found myself were 

 of a dark brown colour. It would appear therefore that 

 this species varies considerably in that character. The 

 body of the sponge is composed of tortuous fistulas anas- 

 tomosing in every direction, the spaces between them being 

 usually very much less than the diameter of the fistulae 

 themselves. The parieties of the sponge are thin and the 

 surface smooth, and I have never found more than one 

 form of spicula in any part, the equiangular triradiate ones 

 of the skeleton ; these spicula are very much like those of 

 L. contorta in size and proportion, but the radii are more 

 obtusely terminated than in that species. 



The cloacal cavity is continuous and totally without 

 defensive spicula, and by this character the species may 

 always be distinguished from L. contorta. 



Dr. Johnston in treating of this sponge says, " There are 

 no fa?cal orifices." 1 have carefully examined a considerable 

 number of specimens with a microscopic power of 160, 

 but have been unable to detect any of the mouths of the 

 cloaca, and attribute this failure to the habit of the animal 

 of closing those orifices at the approach of danger, or while 

 in a state of inaction, and the total absence of internal 

 defensive spicula, would seem to indicate the existence of 

 such a power for its protection from its enemies. In L. 

 contorta the months of the cloaca are at the distal ends of 

 tuberous projections of the sponge, some of these appear 

 fully open, others with a very small orifice apparent, while 

 others are entirely closed, and in this condition no arrange- 

 ment of the skeleton spicula different from that of other 

 parts of the sponge is apparent that would indicate the 

 place of the mouth of the cloaca ; and this may very 



