BY E. F. KALLMANN. 375 



Tedania TENUISPINA. 



The specimen purporting to be the type of this species — and, 

 moreover, the only specimen, either in the collection of tlie Aus- 

 tralian Museum or among the fragments received from the British 

 Museum, which is labelled a?i representing the species — is con- 

 siderably at variance with the description of Tedania tenuispina 

 in regard to its outward form, and departs therefrom also in some 

 other respects, — being, in fact, an example of Stylotella agminata. 

 Nevertheless, in skeletal characters it exhibits, on the whole, a very 

 considerable degree of correspondence with that description ; and 

 were the specimen but possessed of the external habit ascribed to 

 T. tenuispina, one would not hesitate at all to accept it as an 

 example thereof. Accordingly, the question presents itself as to 

 whether the alleged type-specimen should be rejected as wrongly 

 labelled, and as having no relation whatsoever to the species under 

 consideration; or whether the description should be regarded as 

 an erroneous one, combining an account of the external features of 

 one species with that of the internal features of another, the latter 

 species being that which is exemplified by the type-specimen. The 

 evidence is insufficient to enable one to decide positively ; but, for 

 the following reasons, I am disposed to give preference to the view 

 that the description confuses two species, one of which is StijloteUa 

 agminata. In the first place, the external form ascribed to T. 

 tenuispina is opposed to the likelihood of its belonging to Tedania, 

 inasmuch as the species of that genus appear always to be more or 

 less massive in habit; and it is an admissible assumption, therefore, 

 that the species has been either generically misnamed or else mis- 

 described in respect of its external characters. Secondly, the 

 description is open to suspicion owing to an apparent incongruity ; 

 for, in the paragraph relating to the outward characters of the 

 sponge, it is stated that the surface is "roughened by projecting 

 spicules" — which would seem unlikely except in the case of a 

 sponge having spicules of fair length, say, 0-5 mm. or more; 

 whereas, according to the latter part of the description^ the 

 spicules have a length of only 220 /x. Thirdly, no reliance can be 



