Mr. H. J. Carter on Halisarca lobularis. 435 



Ohs. This specimen of Halisarca lobularis, of which the 

 type was originally found by Schmidt in the Adriatic Sea at 

 Subanico, does not differ from his description in any essential 

 point. The pink colour on the prominent parts (stated by 

 Schmidt to be " dark violet " in the Adriatic) goes very soon 

 after immersion in spirit and water, where its original 

 translucence is replaced by whitish yellow opacity. 



The deep triangular puncta or interspaces between the 

 lobules appear to be caused in the way above mentioned, and 

 therefore lead to nothing ; while the surface of the lobules is 

 formed of the papilliforra openings of the pores, which are far 

 too small to be seen with the naked eye, or even any thing 

 below an inch compound power. 



The most remarkable points about the pink coloiu" are : — first, 

 that it is exclusively confined to the spongozoa, whereby it 

 would appear that the coloiu' of sponges generally is seated in 

 the spongozoa, as in Halisarca lobularis ; and, second, that by 

 this pink colour in the living state the form of the sac-like 

 aggregations of the spongozoa can be as distinctly seen as if 

 the latter had been fed with indigo. Lower down, however, 

 the absence of the pink colour renders this differentiation less 

 evident ; while the presence of the indigo here, after the sponge 

 has been fed with it, causes the differentiation to be more 

 striking even than in the pink portions, where the latter colour 

 somewhat obscures it. 



Halisarca ?oZ>i<?a;7 5 differs from H. Dujardinii in the follow- 

 ing particulars, viz. : — H. lobularis/va. the fresh state, islobed 

 and lobulated, tinted pink on the prominent parts, sleek on 

 the sm-face, and provided with sparse vents on a level vf'iXh the 

 surface. H. Dujardinii, on the other hand, in the living 

 state, is miiformly flat and even, of a yellowish grey colour, 

 sleek on the sm'face, and sparsely provided with vents, which 

 are projected above the level of the sponge by a short tubular 

 prolongation of the dermal sarcode. Both may be charged 

 with ova after the manner of sponges generally, as some spe- 

 cimens of the latter from the Isle of Man (lately sent to me by 

 my friend Mr. Higgin, of Livei-pool) testify. 



Having already found two specimens of //. lobularis, and 

 knowing now what to look for, viz. a pink colour, lobulated 

 form, and sleek shining sm'face, I dare to say that I shall 

 often meet with it. 



Of course Schmidt's diagnosis of Halisarca, viz. that it 

 possesses neither siliceous nor calcareous spicules, obtains with 

 Halisarca lobularis. 



