246 Mr. H. J. Carter’s Contributions to our 
living state, might also be found to be so ciliated. Lastly, in 
H. Dujardinit wnder the microscope, it may be observed that 
the spongozoa Ke. are but scantily accompanied by filaments 
of elastic tissue, like that so abundant im the next genus, viz. 
Chondrosia; while in £1. lobularts there seems to be none at 
all; so that im this respect /7. lobudar’s would appear to be 
the most simply formed of the two, yielding, from the absence 
of the elastic element, permanently not only to the pressure of 
objects with which it may come into contact in the  preserving- 
jar,” but, although much thicker than H. Dwardinit when 
treshly laid upon the glass slide, also on this account subsiding 
on being drved into a much thinner stratum. When a frag- 
ment of H. Dujardinw? is placed on a glass slide in water for 
examination, it slips away to the border of the cover, from its 
slimy elastic nature, while that of H. lobularis under the same 
circumstances remains stationary like a bit of soft dough. 
Hence I cannot understand how specimens of the latter found 
by Dr. Ch. Barrois on the north coast of France, nearly oppo- 
site this place, should be termed “‘semi-cartilagineuse” (No. 24, 
p- 42). 
Could the calcareous sponges have originated in AL lobu- 
laris, which, together with the spicules, would be very like 
Ascetta (Clathrina), from the tubular, tortuous, anastomosing 
structure in both being almost identical ? At all events, it is 
remarkable that the earliest forms, according to Hiickel, ot 
the calcisponges, viz. Ascetta, should afford the only analo- 
gous structure among the Spongida, so far as I know, to 
Halisarca lobularis (No. 15, vol. 1. and Atlas). , 
Thus, when carefully examined, there are such strong dif- 
ferences between Halisarca Dwardinti and H. lobularis, that 
it almost becomes questionable whether they should bein 
the same genus. 
Halisarca guttula, Sdt. (no. 5, p. 41, and Taf. v. fig. 2, 
No. 9), is thought by Schulze to be the same as his (Schulze’s) 
H. lobularis purpurea (No. 26, Taf. i. fig. 5). 
Giard’s Halisarca mimosa (mimic) from Boulogne, which, 
according to his description, consists of a thin lamina with 
plane surface, of a brick-red colour varied with orange-yellow, 
having its oscules bordered with deeper red slightly carmine, 
from which radiate orange-coloured lines, like “ ascidian ani- 
malcules”’ (no. 18, p. 488), requires confirmation. And the 
other species, which was found at Roscoff, although so like Z. 
lobudar’s that Schulze conjectured it to be the same as his 
variety, viz. £1. lobularis purpurea (No. 26, p. 45, Separat- 
Abdruck), differs from “7. dobular’s in being “ semi-cartilagi- 
neuse ’’ in consistence, and the specimens possess “ une grande 
