1905,] SPONGE CLATHRINA CONTORTA. 5 



was really a specimen of variabilis, while the specimen of contorta 

 of which the spicules were figured (l. c. figg. 8, 9, 10) was really a 

 specimen of complicata ; and that amongst nine of Bowerbank's 

 specimens examined by me I have found four distinct species 

 confused together — to wit, complicata, variabilis, coriacea, and 

 " Ascetta spinosa Lendenfeld" : I think it is not necessary to say 

 more in support of the statement that Bowerbank's species 

 contorta was of absolutely no systematic value whatever, but 

 represented merely an ill-defined jumble of difierent species. 



In 1872 Haeckel, in his ' Kalkschwamme ' [2], used Bowerbank's 

 specific name contorta for a sponge which he described in detail. 

 Haeckel pointed out quite rightly that the external characters of 

 contorta as set forth by Bowerbank were no guide whatever to its 

 identification, since a quite similar mode of growth characterises 

 other Ascons. Haeckel therefore diagnosed contorta by details of 

 its spiculation. The diagnosis given is incorrect in two points, 

 namely, in stating that the monaxons possess a lance-head at 

 their distal extremity, and that the gastral rays of the quadri- 

 radiates are " curved oralwards " ; two statements that lead me to 

 suspect that Haeckel's material of contorta was, like Bowerbank's, 

 contaminated by admixture of Leucosolenia comp)licata. Haeckel, in 

 his description, also affirmed, in his usual manner, definite characters 

 in the spiculation Avithout taking into consideration the variability 

 which is so marked a featm-e of the sponge. It is a puzzle to me 

 how Haeckel a.rrived at the definition which he gave of Ascanch'a 

 contorta, since the specimens named and identified by him which 

 I have seen do not agree with his description, and belong, indeed, 

 to other species — a fact which easily explains any errors of 

 description on his part. It is even more mysterious that Haeckel 

 should have considered his contorta identical with Bowerbank's 

 contorta, since, of Bowerbank's specimens examined by me, eight 

 in all, not one agrees with Haeckel's diagnosis ! These enigmas 

 are not, however, of importance to the present enquiry. Taking 

 Haeckel's description as it stands, and allowing for a certain 

 margin of inaccuracy, I have been able without difficulty to refer 

 to Haeckel's Ascandra contorta a sponge extremely abundant on 

 the Mediterranean coasts of France, and occuriing elsewhere 

 also. As I have stated in a previous memoir, I consider that 

 where previous writers leave us ia doubt as to the characters of a 

 species, Haeckel's description fixes the application of the name. 

 I will proceed now to describe the sponge which I regard as the true 

 contorta, and then to consider the synonymy and application of 

 the name. 



Ascandra contorta H. is a species which, for reasons stated 

 elsewhei-e [4, &c.], I refer to the genus Clathrina Gray (1867). It 

 has a closely reticulate mode of growth, equiangular triradiate 

 systems, collar-cells with basal nucleus, and parenchymula larva ; 

 all these being characters which make up my diagnosis of the 

 genus Clathrina. 



