Geodia? sp. 
(Plate II, figs. 13, 14, 15), 
Spicules with an elongated, moderately robust, straight, 
shaft, having a constriction at the upper end, below which, 
in some specimens, there is a slight inflation; the shaft 
gradually tapers to a point. The rays of the head are short, 
slightly curved at their junction with the shaft, then straight 
and pointed. They extend forwards nearly ina line with the 
shaft itself. Specimens with the rays bifurcate or compound 
are equally as numerous as those with the rays simple. These 
spicules are well characterized by the constriction at the top 
of the shaft and by the manner in which the head-rays ex- 
tend directly forwards. The length of an average specimen 
is 2,29 mm.; thickness of shaft 0,135 mm.; and width across 
the head 0,2 mm. A spicule with a similar diposition of the 
head rays but apparently a larger form, is figured from the 
North of Ireland (Wright: op. cit. Pl. Il, fig. 22). 
This and a few other forms of spicule, described below, 
in which the head rays are either directed forwards or else 
recurved, appear to resemble those spicules of Mr. Carter's 
group of the Pachytragidae which he has termed «anchoring» 
spicules and it is probable that they were associated with 
the larger trifid spicules, which I regard as the «zone» spi- 
cules of the same division of sponges. As a rule these fossil 
«fork» and «anchor» spicules are much larger than those in 
existing sponges, but this might be expected from the greater 
dimensions of the «zone» spicules. 
Geodia, sp. 
(Plate Il, figs. 17, 18, 19). 
Somewhat delicate spicules with an elongate gradually 
tapering shaft, and simple, straight or curved, pointed rays 
extending forwards from the shaft. The rays are frequently 
