^04 



ENDEAVOIR' SCIENTIFIC EE8ULTS. 



(a) Accordini^ to Lendeiifeld : — 



P. (■/(':,>•<; »/.\. A ifticulate mass of regularh' cvlindri(\\l 

 branches on an average 5 mm. thick ; spicules, 

 smooth styli 160 x 6 ^ and 70 x 5 j(, the latter echin- 

 ating. (Loc, Port Jackson.) 



P. arbofcu. Dendritically ramifying, with clearlv- 

 detined stem. The styli measure 80 x 4 /i and 50 

 X 4 K respectively. (Loc, Port Jackson.) 



P. ))iacr()poni. Small and tender, reticulate, hone\ - 

 comb-like, incrusting or massive ; smooth styli 200 

 X 4 ;< ; echinating spined styli 70 x 6 //. (Loc, 

 Torres Strait.) 



ih) ,\c(-ording to Whitelegge : — 



P. ch'i^aus. With erect, rarel} coalescent branches, 

 generally with distinct peduncle; spicules, styli 100 

 X 6 ]i and 80 x 5 >< respecti\ ely. (Loc, Port Jackson 

 and neighbourhood.) 



P. arhona. A CUithria; reticulately branched in one 

 plane ; spicules, styli 180 x 8 jt, subtylostyli 200 x 2 //, 

 acanthostyles 85 x 6 /<. (Loc, Port Jackson and 

 neighbourhood. ) 



P. uiacfopora. Forming low densel} -branched clumps, 

 with abundant anastomoses of branches. Spicules, 

 smooth styli 100 x 4 }i and 75 x 4 ;< respectively. 

 (Loc, neighbourhood of Port Jackson, common.) 



A comparison of the description^ of P. arborea, Lendf., 

 and P. elegans, Whitelegge, points almost incontestably to 

 the conclusion that they are one and the same. Clathria 

 {Plcctispa) arburea, Whitelegge, is therefore quite a different 

 sponge from Lendenf eld's species and requires a new specific 

 name, for which I propose nndtipcs. E china clathria {Plec- 

 iispd) macropora, VVhitelegge, is, as mentioned, a common 

 local sponge, and must have been familiar to Lendenfeld. It 

 ■evidently affords no grounds for its identification with P. 

 tuiicropora, Lendf., which, moreover, is recorded from a 

 widely distant locality. Neither does it show sufficient agree- 

 ment with P. elcgans to warrant its identification to that 

 species. There is no other course open but to regard it as a 

 new species ; it is described in the present paper under the 

 name of Echinochithria raniosa. P. arborea, Lendf., is like- 

 wise a species of Ecliinochiiliria, and there can be little doubt 

 that P. elegans, Lendf., belongs to the same genus. The 

 -genus Plectispa is accordingly left with a single species, P. 

 viacropora, which may therefore be considered as the type. 



