Sponges from South Australia, 291 



useful, for I know of no exception to it. But it does not applj 

 so satisfactorily to the second family, viz. the Axinellida ; 

 neither does the special diagnosis of this family, viz. : — 

 " Echinated with proper spicules projecting from the interior of 

 the fibre," suffice for all, since it may be the case to a certain 

 extent with species of the Rhaphidonema ; but by adding 

 the words : — " Structure increasing in density inwards or 

 towards the first-formed parts, that is the axis," which for the 

 most part is &, peculiarity conxraoii to the whole order, although 

 not needed in the diagnosis of the first family, that of the second 

 family is rendered almost equally useful. 



It will be observed by referring to the above '' table " that 

 each of the families commences with a " group," whose name 

 etymologically has the same signification, viz. '* Pluriformia " 

 and " Multiformia," which, as before stated, vioxt provisionally 

 instituted, because the specimens which appeared to belong- 

 to them respectively were at the time of classification so 

 numerous as to be quite overwhelming ; therefore all that I 

 could do under the circumstances, that is with little or no 

 literature for my guidance, was to keep them together, as I 

 have before observed of the Psammonemata, under the 

 families mentioned, for subsequent division into groups when 

 their species, by individual description from undried and 

 entire specimens, should be typically determined. It was 

 this to which my dear old friend Dr. J. E. Gray alluded 

 when he said : — " The greatest contributor to our knowledge 

 and advancement of spongiology in its present state will be 

 he who correctly describes and illustrates most species." 



Fam. 1. Ectyonida. 



Group 1. Plueifoemia. 



In the "key" to my classification [1. c. p. 195) I have 

 given the names of several kinds of sponges which I then 

 thought might become types of the subdivisions of this group, 

 and during the kst ten years which have elapsed since that 

 was published I have occasionally been able to substantiate it 

 thus: — '•''Ectyon sparsus'''' has led to the formation of the 

 group "Ectyonina" or "Ectyones" ('Annals,' 1883, vol. 

 xii. p. 310, &c.) ; ^^ Echinonema typicum " to one for which I 

 would propose the name of " Echinonematina " [ih. 1881, 

 vol. vii. p. 378, &c.) j ^^ Dictyocylindrus ramosus, Bk.," &c. 

 to that of " Dictyocylindrina " {ib. 1879, vol. iii. p. 295) ; and 

 ^^Spongia mwicataj Pallas, = Trikentrion wiwrzca^t^m, Ehlers," 



