THE JURASSIC FLOE A OF SUTHERLAND. 701 



threads associated with a gradually tapered stalk, which on closer inspection is seen to 

 be characterised by the presence of numerous parallel veins and is possibly part of a 

 Phcenicopsis leaf. It may be that the association in this case between mop and stalk 

 is accidental, while in the larger specimen (fig. 38) there is organic continuity. On the 

 other hand, it is by no means improbable that the mops are the remains of some filament- 

 ous alga which grew epiphytically on pieces of larger plants. The mops appear to be 

 denser in the centre, gradually shading off as a fainter and vaguely delimited stain at 

 the periphery. 



An interesting feature of these impressions is the association of small white spicules, 

 simple and branched, which suggested the presence of sponge fragments. The spicules 

 are most abundant in association with the mop-like heads, though they also occur 

 scattered over the stalks and other parts of the rock. I submitted the specimens to 

 Dr Hinde, who very kindly sent me the following notes : — 



" Further examination of the slab of rock confirms my view that the sponge spicules 

 which occur on the carbonaceous axes and their moss-like heads, and are dispersed more 

 or less thickly throughout the rock, are not specially connected with the carbonaceous 

 bodies, and I do not think that the sponges to which they belonged were attached for 

 support to the plant remains. I can make out four kinds of the siliceous spicules ; 

 possibly there may have been others, now too fragmentary for recognition ; the forms 

 are : straight or slightly curved, fusiform (text-fig. 14, B) ; trifid spicule with short 

 horizontal head-rays, sometimes recurved (fig. C) ; four-rayed spicules (figs. D, F) ; 

 dermal spicule of tetractinellid sponge (fig. E). All these forms are common types and 

 may be found in pretty well every fossil deposit of sponge spicules, whether Cretaceous 

 or Tertiary, and they are also present in recent dredgings. Nos. 1 and 2 (figs. B, C) 

 might belong to a form of Stellata ; Nos. 3, 3a (figs. D, F) to Pachastrella. The 

 spicules in these sponges are not organically connected, and thus are readily detached 

 and scattered after the death of the animal. It is possible that the circular expansion 

 on the right of the slab may represent portions of two small specimens of Stellata, for 

 the spicules are all of the same kind of trifids. I have not recognised any spicules of 

 Lithistid or Hexactinellid sponges. It is unusual, in my experience, to find sponge 

 remains in a rock associated with such a number of plants." 



D. ? Podozamites sp. (Text-fig. 10, C.) 



The single leaf, incomplete at the base, represented in text-fig. 10, C (p. 685), shows 

 a few slightly spreading veins which appear to fork near the obtuse apex. This solitary 

 specimen occurs on the back of the slab with the impression of Nilssonia orientalis 

 reproduced in photo. 42, PL IX. Accurate determination is impossible ; but a com- 

 parison may be made with Podozamites sp. figured by Yokoyama * from Japan and 

 with Podozamites obovatus described by Schenk from the Wernsdorf beds. t Leaves of 

 similar form are figured by Berry in his species Araucaria Bladenensis.\ The leaflet 

 * Yokoyama (94), pi. xxv. t Schenk (71 2 ), pis. ii., iii. \ Berry (08), pis. xii.-xiv. 



