276 Dr. W.C. M‘Intosh on the Boring of certain Annelids. 
HYALOoTHRIX, Gray, P, Z. 8. 1867, p. 119. 
Bark smooth. Polypes oblong when contracted, low. Ten- 
tacles 40. 
Hyalothrix lusitanica, Gray, 1. c. 1867, p. 119. B.M. 
Type Hyalonema lusitanicum, Bocage, P. Z. 8. 1864, p. 265, t. 22; 1865, 
p- 662; Gray, Ann. & Mag. Nat. Hist. 1866, xvii. p. 287; Lovén, Ann. 
& Mag. N. H. 1868, p. 90. 
Var. spongifera. 
H, lusitanicum, Bocage, Ann. & Mag. Nat. Hist. 1868, 11. p. 86; Bow- 
erbank, P. Z. 8. 1867, p. 902. 
Hab. Portugal. 
P.S. Dr. Perceval Wright, who has just returned from 
dredging for Hyalonemata on the coast of Portugal, informs me 
(Sept. 14) that he believes the coral (77. lus’tanicum) grows at 
the bottom of the sea in deep water, with the free part of the 
coil sunk in the sand. He also mentioned to me that M. Bo- 
cage has some specimens of the sponge that grows on the H. 
lusitanicum with a shallow cavity that is covered with a netted 
lid formed of spicules, like the lid of Huplectella. I do not 
find any trace of such a lid in the three sponges on the Hyalo- 
nema Steboldii in the British Museum; but it seems to exist 
in some specimens of that sponge, as Dr. Lovén says that Prof. 
Schultze found “the flattened surface of the smaller and 
younger specimen (No. 4) covered by a network of spicules 
similar to that which covers the free end of Huplectella.” 
(Ann. & Mag. N. H. 1868, ii. p. 89.) 
XXXIIL—On the Boring of certain Annelids. 
By W. C. M‘Intosu, M.D., F.L.8.* 
[Plates XVIII, XIX., XX.] 
At the Meeting of the British Association held at Dundee, 
my friend Mr. E. Ray Lankester read a very interesting paper 
on “ Lithodomous Annelids,” or, rather, on the boring of 
Sabella saxicava, Quatref., and Leucodore ciliata, Johnst., 
chiefly with reference to the latter. In the discussion which 
followed, Mr. Gwyn Jeffreys and I strongly opposed the 
theory advocated by the author as to the action of a purely 
chemical agency in the production of the perforations. I spe- 
cially mentioned that Leucodore ciliata bores in aluminous 
shale—a fact fatal to the chemical (or acid) theory—and am 
* Communicated by the Author, having been read at the Meeting of 
the British Association at Norwich, Aug. 24, 1868. 
