308 PLATE LXXXVIII. 



found in considerable numbers at one locality at the 

 mouth of the Mersey, and that the largest he has seen 

 was eight inches in height with a lateral spread of 

 about six inches ; and among other specimens sent 

 to me from the Liverpool Museum for examination 

 there was a specimen of J. varians of a rudely palmate 

 form rather less than two inches in height and 



o 



rather exceeding half an inch in breadth. No two of 

 the larger specimens that were sent to me were alike 

 in form, and one of them eight inches in height had 

 no appearance of the compact clustered form exhibited 

 by the figured one, but consisted of numerous slender 

 ascending branches dividing dichotomously at intervals, 

 and the greatest lateral spread did not exceed two 

 inches. This species appears to be quite as variable in 

 the mode of the disposition of its branches, as Chalina 

 oculata, which it closely resembles, but whatever their 

 height and size may be, they always appear to be very 

 much more slender and delicate than those of C. 

 oculata, for which they might otherwise be very readily 

 mistaken if judged only by their external characters, 

 and this error is the more likely to occur as the 

 disposition of the oscula in both species is alike. In 

 structural characters, whatever may be the size of the 

 specimens, they all agree with those of the little type 

 one in the British Museum. 



In the description of the specific characters of the 

 type-specimen, page 281, vol. ii, I have stated " surface 

 smooth and even." In these better preserved speci- 

 mens the surface is minutely hispid by the prolonga- 

 tion of the primary lines of the skeleton. 



The increased knowledge that we have obtained of 

 the structural peculiarities of this sponge renders it 

 necessary that we should reconstruct its specific cha- 

 racters, and I propose that the following should be sub- 

 stituted for those in vol. ii, page 281, 'Mon. Brit. 

 Spongiadse.' 



