1904. J SPONGES OF THE GENUS LEUCOSOLBNIA. 351 



form which enables one to recognise it almost with certainty, or 

 at least to distinguish it from others belonging to the same fauna 

 by simple inspection. That is the case particularly with Leucoso- 

 lenia hotryoides, the first-named Ascon species described in 1786 

 from the British coast (locality Emsworth, between Sussex and 

 Hampshire) by Ellis and Solandei- [7] under the name Sjiontjia 

 hotryoides. In this case the form is so charactei-istic that thei-e 

 can hardly be any doubt as to the species Avhich is represented by 

 the authors' figure. The next species of Leucosolenia to be 

 described was the Spongia complicata of Montagu [17], also from 

 the British coast ; and in this case it is moi'e difficult to be 

 positive, but, on the whole, it is highly pi-obable that Montagu's 

 figures rej)resent a specimen of the sponge for which his name 

 is retained, following Haeckel, in this memoir. The ai-borescent 

 mode of growth depicted is a feature extremely characteiistic, if 

 not absolutely distinctive, of this species, at least as far as the 

 British fauna is concerned. On the othei' hand, more doubt 

 attaches to the third species described, the Sjiongia confervicola of 

 Templeton, 1836 [22], which is evidently a Leucolosenia fi'om the 

 figures, but of which the specific identity remains doubtful. 

 Templeton's memoir is freely annotated by " G. J.," apparently 

 George Johnston, and the footnote to 8. confervicola is ^'- t^pongla 

 complicata G. J." I am more inclined to the opinion, however, 

 that the figure of 8. confervicola represents a specimen of the 

 later described species '■^ Ascandra variahilis" of Haeckel, though 

 Haeckel himself identifies it with hotryoides. In any case, as the 

 point cannot be determined, Bpongia confervicola must be re- 

 garded as a nomen mulum without importance for taxonomic 

 nomenclature. Johnston, in his work of 1842 [14], ignores both 

 Spongia compilicata, as Fleming [8] had done before him, and 

 *S'. confervicola ; both these authors recognise only Spongia 

 hotryoides, and regard Montagu's S. complicata as merely a variety 

 of the former. 



In the meantime diffei'ent authors had subdivided the compi-e- 

 liensive genus Spongia into various genera, and Templeton was 

 one of the last to employ the name for any calcareous sponge. 

 Fleming in 1828 [8] proposed the generic name Grantia for all 

 calcareous sponges, putting G. compressa Fabr. as the first, and 

 G. hotryoides Ell. & Sol. as the second species; compressa must 

 therefore be regarded as the type species of Grantia. Giunt in 

 1833 [11] proposed the genus Leuconia for calcareous sponges, 

 putting as his first sjDecies nivea, which is therefore the type 

 species of this genus. In 1834 de Blainville [6] proposed the 

 name Calcisjyongia in exactly the same sense as Grantia, putting 

 also comjyressa first and hotryoides second, so that this generic 

 name becomes a synonym of Grantia. A great advance was made 

 by Bowerbank [1], who, in 1864, further subdivided the calcareous 

 sponges. Pointing out that Grantia hotryoides was quite difierent 

 from either the G. com2)ressa (Fabr.) or G. nivea (Grant) of 

 Fleming, he retained Fleming's genus Grantia for compressa, 



