8 
MARINE SPONGES. 
Observations. — Hymeniacidon carnosa, Bk. = Suberites 
Nardo, apud Schmidt, is generally stipitate, but may be simply 
contracted and sessile towards the base ; it contains no flesh- 
spicule. 
Halichondria Pattersoni may be known by its dark brown 
colour and spiculation. 
Hymeniacidon suberea, Bk. = Suberites domuncula, Nardo, ap. 
Sclnnidt, generally grows over a gasteropodous shell tenanted 
by a hermit crab ( Payurus ), and deposits its ova on the surface 
of the upper or remaining part of the shell (see Ann. Mag. 
Nat. History, 1883, vol. xii., p. 36) ; while it differs among 
other things from H. carnosa , in possessing the little centrally 
inflated flesli-spicule common also to H. ficus, &c. Dr. Bower- 
bank seems not to have noticed this, as it is omitted in his 
illustrations of II. suberea (/. c .) and said (vol. ii., p. 208) to 
be characteristic only of H. ficus , &c. I enclose for your 
acceptance some dried specimens of H. suberea dredged off 
this place (Budleigh-Salterton, S. coast of Devon), one of 
which has been divided vertically to show the ova, &c., in situ. 
Of Microciona armata, Bk., there is only one specimen 
which has grown over the ventral valve of a Brachiopod 
(? species). 
Halichondria panicea, Bk. = Amorphina, Schmidt, is a deep- 
sea as well as a littoral species, apparently the most plentiful 
of all, all over the world ; in which the only difference appears 
to be in the size of the spicules which are smallest in the 
latter. 
Isodictya fucorum, Bk. = Halichondria fucorum , Johnston ; 
may be known by its habit of growing over the stems ofFuci, 
together with its spiculation, in which there is a little equi- 
anchorate flesh-spicule of the navicula-shaped kind. There 
is very little difference between this and Isodictya aided, Bk., 
as I have learnt from an examination of the type specimens 
of these species now in the British Museum. 
Of the Debris I can add nothing to what has been above 
stated. 
Thus, in point of general classification, Halichondria panicea 
and H. Pattersoni, respectively, belong to the groups Nos. 1 
and 6 in the first family of my order Holorhaphidota, viz., the 
Renierida (Ann. Mag. Nat. History, 1875, vol. xvi., pp. 177 
and 190). Hymeniacidon carnosa and H. suberea to the second 
family, viz., the Suberitida. Microciona belongs to the 
Microcionina in my order Ecliinonemata, and here also I 
should be inclined to place Isodictya fucorum chiefly on account 
of the form of its skeletal spicules and the presence of the 
little navicula-shaped equianchorate. 
