[DAWSON] FOSSIL SPONGES AND OTHER ORGANIC REMAINS 



118 



the appeurance of a rounded bawket wit li strong vertical ribs and very 

 slender horizontal bars, within which and at top were quantities of slender 

 straight spicules, 



12. — Lasiothrix flabellata, s. n. 

 (Fig. 25.) 



Fig. '2^.— Lasiothrix flabellata. Restored, 

 and spicules x 5. 



I have some doubt as to the right of this species to be placed in Dr. 

 Hinde's new genus; but the specimens much resemble the former species, 

 and may accompany it provisionally. The surface appears to be covered 

 with small ovoid bundles of stout biacerate spicules, diverging from the 

 centre and sometimes in fan-shaped tufts. The specimens show indications 

 of an external membrane, and they had somewhat strong root spicules, 

 much larger than those of the body. It seems uncertain whether the fan- 

 shaped bundles are really such or flattened groups of radiating spicules 

 surrounding small oscula. In some specimens the spicules are confusedly 

 scattered in films of pyi'itous matter with little indication of radiating 

 arrangement. Dr. Hinde remarks as to this form that '' the spicules do 

 not stand out definitely, as in the case of the hexactinellid sponge spicules, 

 ':- .t appear to ue imbedded in some membrane. Ir two instances, anchor- 

 ing-spicules, like those of Protospongiii, project from the base of the 

 mass. I do not know^ of an}* monaetinellid sponge furnished, as these 

 appear to have been, with long anchoring-spicules." 



The sponges of this genus are very rare in the Metis collections, and 

 are obscure and difficult to make out as to their details. 



