SPONGES.-HALLMANN. 243 



skeleton of slender fibres cored by straight or curved styli 

 200 X 4 li in size, and pretty abundantly echinated by slightly 

 spined styli 70 x 6 p in size. Microscleres are not mentioned. 



Clathna mollis,^ Kirkpatrick. A sub-caliculate sponge of 

 soft consistency, with scattered oscula. Skeleton a reticula- 

 tion of thick soft fibres echinated and sometimes cored by 

 acanthostyles, 130 x 11 /i in maximum size. Foreign bodies 

 present in the fibres and ground substance. Asymmetrical 

 amphitornota, 165 x 5-5 /i, occur in the dermal layer. Micro- 

 scleres: tridentate isocheUe, sigmata, and [?] toxa. 



The last-mentioned species differs from all the preceding in 

 the tact that the non-accessory megascleres are diactinal, but 

 this does not provide sufificient reason for excluding it from 

 the genus, since in a number of the other species a diactinal 

 tendency on the part of these spicules is frequently to be 

 obserxed. 



The sponge described by Carter under the name of Wilson- 

 ella echinonematissima^ might perhaps also," for the present, 

 be included amongst the species of Wihonella. It is, how- 

 ever, peculiar in the fact that the acanthostyles are dif- 

 erentiated into two kinds, a larger and a smaller ; the former 

 attain a size of 145 x 8.3 p.. The sponge is massive, with a 

 reticulate skeleton of horny fibres which are echinated by the 

 acanthostyles, and in the deeper parts of the body cored with 

 smooth sub-basally constricted smooth styli, about 210 x 4 jx 

 in size, but which towards the surface become almost ex- 

 clusively occupied by foreign bodies. Oscula (?). The micro- 

 sclere is "an equianchorate somewhat bent upon itself, rather 

 obtuse at the ends, i.e., not navicularly shaped," measuring 

 25 ff in length. 



Also it might be well to include provisionally, as species 

 duhicB, under the genus Wilsonella, Lendenfeld's three so- 

 called varieties of Echinonema nnchoratum, Carter. The 

 type-specimens of these three sponges appear to have been 

 lost, and since their descriptions are very brief, it is possible 

 that they may never be re-identified. It is strange that 

 although Carter clearly indicates in his description of E. 

 anchorata that the megascleres are styli, Lendenfeld in his 

 description of the "varieties" states that they are oxea ; but in- 

 asmuch as the latter has described the non-accessory megas- 

 cleres of his Echinonema levis and E. rubra as styli, whereas 



1 Kirkpatrick— "Marine Investigations in South Africa," ii.. Sponges 



iii., p. 249, pi. v., fig. 15, pi. vi., figs. 16a-d. 



2 Carter— Ann. Mag. Nat. Hist. (5). xvi., 1881, p. 366. 



