436 
THE VOYAGE OF H.M.S. CHALLENGER. 
or single, and then forming the simple termination of a long narrow canal, which com- 
pletely traverses the cortex. Cortex thick, usually differentiated into a collenchymatous 
outer and a fibrous inner layer. 
Spicules. — I. Megasclere. 1. Strongyloxea, of the same form as in Tethya ingalli 
and Tethya seychelle7isis, from 1'6 by 0‘0193 mm. to 2‘54 by 0‘0387 mm. 
II. Microscleres. 2. Cortical spheraster, very variable in form, centrum always 
large, actines conical, oxeate ; smooth or sparsely spined, or dichotomose ; from 0’039 
to 0‘097 mm. in diameter. 
3. Somal and choanosomal asters similar ; both very variable, a centrum is usually 
present, the actines are conical or cylindrical, oxeate, or more usually truncate or 
strongylate, from O'OllS to 0'02 mm. in diameter. 
Colour. — Dull orange to bright chrome-yellow when alive, greyish-white in spirit. 
Habitat. — Mediterranean Sea : — the Adriatic (Quarnero, Zlarin, Lesina, Corfu), coast 
of Algiers. English Channel : — South Devonshire (Plymouth, Budleigh Salterton, 
Torquay), Cornwall (Towey Harbour), Sussex (Hastings), Guernsey (Tremaine Bay, 13 
fathoms), Brittany (Roscoff, Isle of Douon, lowest spring tides). Atlantic Ocean : — 
Ireland (Westport Bay, county Mayo and Connemara), West Florida. German Ocean: — 
Norway (from Trondjheim to the North Cape; Kors Fjord, 180 fathoms). Arctic 
Ocean: — Lat. 71° 12'.5' N., long. 20° 30' E., 135 fathoms; lat. 72° 9' N., long. 
24° 42' E., 145 fathoms. 
Remarks. — The general agreement of zoologists to call this sponge Tethya lyncurium 
is opposed by Carter, who advocates the claims of Donatia aurantium. In the 
following short history justification is found for the accepted view. Partly owung 
to the well-marked characters of the sponge, partly to the truthfulness with which 
they are portrayed by Donati, there is no mistaking the species which this clear- 
sighted observer intended in his description commencing “Tetie sferica . . . .” 
These two words, however, do not constitute a name in the Linnean sense, and, as they 
are pre-Linnean, may be dismissed. Linnaeus then named the sponge Alcyonium 
lyncurium (1767), and “lyncurium” as the specific designation is therefore happily 
inalienable. 
Pallas, however, in his excellent description (1776) unfortunately adopted another, 
and the name “ awantium” given by him is that advocated by Gray and Carter; I do 
not precisely see on wFat grounds. The sponge is so readily recognised, even without 
microscopical examination, that it must have been perfectly well known to the naturalists 
of Linnaeus's time and to their immediate successors ; Lamarck and Lamouroux identify 
it and adopt Linnaeus’s name without hesitation. 
The discussion is thus narrowed down to the selection of the generic name. Lamarck 
is author of the genus Tethya, or as he sometimes spelt it “ Tethea,” but under this name 
