540 REVISION OF THE MONAXONIC SPONGES, il., 



description. This, however, is not the case, for I have since 

 found the actual specimen from which the figure was taken, 

 and it is a comparatively quite small sponge ; it is labelled in 

 Lendenfeld's handwriting with a name (^' licmodaihr'ia arhus- 

 cula'^) which is given in the key-list as the manuscript syno- 

 nym of Clathrlodtndron arhuscula, but even this information 

 is incorrect, for it proves to be a new species of lias'pa'dia — E. 

 afjminata {vide Appendix). 



Halichondria mammillata. 



In the case of this species, neither the ostensible type-speci- 

 men in the Australian Museum nor the specimen labelled as 

 representing it in the British Museum is in the least capable 

 of being reconciled with the description of the species ; and, so 

 far, I have met with no sponge to which the name Hallchon- 

 dria marmnUlata is, in my opinion, applicable. The specimens 

 in question have already been referred to by Whitelegge, from 

 whose remarks one would gain the impression that the former 

 is undoubtedly a genuine example of the species and that 

 therefore Lendenf eld's description simply is inaccurate with 

 respect to the dimensions of the spicules. In point of fact^ 

 however, this specimen is quite as much at variance with the 

 description in external as in internal features, being a tubu- 

 lar digitate sponge belonging to an (apparently undescribed) 

 species of Siphonochalina. The British Museum specimen, on 

 the other hand, has a skeleton consisting almost entirely of 

 foreign spicule-fragments (but conta^ining in addition proper 

 spicules in the form of scattered slender strongyla and sigma- 

 ta) and belongs to an undetermined species of CJiondrojJsis. It 

 is possible that the latter, of which I have seen only a frag- 

 ment, is an example of the species described by Lendenf eld in 

 his "Monograph of the Horny Sponges" under the name of 

 Stf/mf( fella {i.e., Chondro2)si.s) rorficdfd vsly. mannndldris, and 

 accordingly that it possesses external features very similar in 

 kind to those ascribed to Il(d'\rhoudr\a mammdlata. If this 

 should prove to be the case, there would be reason to suspect 

 that the description of Halichondria mammillata was based 



I 



