50 DAWSON AND HINDE 



of distortion, cruciform spicules with one ray curved, and minute stellate spicules. 

 The whole somewhat resembles, though with difference in detail, the debris of the 

 body of the modern Hyalonema, when crumbled and examined under the microscope. 

 Associated with these jîatches, and also found separate, are many large anchoring rods 

 of peculiar structure. They consist of seAa^ral slender spicules twisted together spirally 

 so as to resemble a rope. Each strand has little tubercles externally to give greater 

 holding power, and the whole, when well preserved, constitutes one of the most beau- 

 tiful of sponge structures. In one or two cases the spiral threads were seen to be 

 unwound at their proximal ends, as if passing into the slender rods of the body of the 

 rponge. A tendency to such spiral rolling appears in the modern glass-rope sponge 

 (Hyalonema Sieboldii), and the little frills on its root spicules may represent the tubercles 

 of the strands in the present species. A similar structure has been found by Dr. Hinde 

 in the root spicules of Hyalostelia fasciculus, McCoy, from the Siluro-Cambrian,' and a 

 specimen apparently of the same species in my collection shows this structure, though 

 less perfectly than the specimens from Metis. 



The connection of these anchoring rods with the patches of scattered spicules is of 

 course inferential, but they are constantly associated on the slabs of shale, and such roots 

 are not found attached to any of the other species, though, as already stated, similar roots 

 may have been present in Acanthodictya. 



Imbedded in some of the patches of Hyalostelia are oval bodies, about a centimetre 

 in their longest diameter, destitute of roots or defensives and composed of crowded 

 cruciform spicules of minute size resembling those of P. delicatula. I was at first 

 disposed to regard these as gigantic ovarian capsules, but Dr. Hinde thinks they are more 

 probably small sponges of some other species accidentally introduced. 



Genus LASIOTHEIX, Hinde. 



Sponges small, depressed oval in outline, the outer surface covered by a layer ot 

 longitudinally arranged, apparently simple, acerate spicules ; beneath this is another layer 

 of spicules disposed transversely. From the base of the sponge several simple elongated 

 spicules extend. 



The peculiar arrangement of the surface spicules in this form indicates a probably 

 new genus, but in its present condition one cannot tell with certainty whether it is 

 monactinellid or hexactinellid. The outer surface seems to have been invested with a 

 sheathing of regularly arranged acerate spicules, and beneath these other spicules, disposed 

 transversely, can be distinguished, but whether these are really acerate or modified 

 hexactinellid spicules there is no decisive evidence to show. In one or two instances, the 

 spicules appear to be cruciform, and the presence of the long simple anchoring spicules 

 extending from the base of the sponge, precisely as in normal hexactinellids, is a further 

 point in favor of its belonging to this division. 



• British Fossil Sponges, Pal. Soc, 1888, PI. i. fig 3. 



