364 A MONOGRAPH OP THE 



racters in the first paragraph from Montagu's description, 

 quoted above, of very Uttle value, and the figure and de- 

 scription of the form of the specimen in the second para- 

 graph, is so opposed to that of the labelled specimen in 

 Dr. Grant's possession, as to render it highly probable that 

 it is not the type specimen described by Montagu. I fear, 

 therefore, that the doubt appended to Dr. Johnston's 

 description of " Spongia ? lavigata" in his ' History of 

 British Sponges/ must be considered as conclusive against 

 its claim to be a Spongia, and especially so, as I have not 

 yet met v^ith a British sponge which would seem to favour 

 such a conclusion. 



2. Chalina cervicornis, Bowerhanh. 



Halichondkia ceevicobnis, Johnston. 



Sponge. Pedicelled, slender, branching dichotomously or 

 trichotomously. Surface even, smooth. Oscula and 

 pores inconspicuous. Dermal membrane unknown. 

 Skeleton. Diffuse and somewhat irregular; primary 

 lines cylindrical ; radiating sinuously from the base to 

 the apex of the sponge, sparingly spiculous, occa- 

 sionally aspiculous ; secondary lines irregular, rarely 

 more than unispiculous ; spicula acerate, rather short 

 and stout, irregularly (Tisposed. Interstitial membranes 

 obsolete. 



Colour. — In the dried state, dull green, verging to amber 

 yellow. 



Habitat. — Frith of Forth, Johnston. 

 Examined. — In the dried state. 



I have seen no other specimens of this species than those 

 preserved in the Johnstonian collection of sponges in the 

 British Museum, labelled 47.9.7, 1447'' and T, and both 

 of them have been so well washed that none of the mem- 

 branous tissues could be found remaining, so that the 



