LOWER AND UPPER GREENSAND OE THE SOUTH OF ENGLAND. 
441 
strongly bifurcate, and the subdivisions usually diverge widely from each other. 
Total length from 1'07 to 177 mm. ; width ‘112 to ‘16 mm. Bays '17 to "5 mm. in 
length by 7 mm. in thickness. 
L. G. S., Haslemere. U. G. S., near Warminster, Merstham. 
26. Geoclites dejlexus (Plate 42, fig. 10).—Zone spicule, with straight, very gradually 
tapering shaft; the rays simple, extending for two-thircls of their length at approxi¬ 
mately a right angle to the shaft, and then abruptly recurved. Total length unknown, 
the shaft is • L mm. in width. Rays ‘375 mm. long by '087 mm. wide. 
U. G. S., Blackdown. 
27. Geodites Wrightii (Plate 42, fig. 9; Plate 41, fig. 13).—Zone spicules with straight 
tapering shaft and stout rays, projecting obliquely forwards. The rays are incipiently 
bifurcate at their extremities. The rays and the greater portion of the shaft are 
moniliform. Length 1'375 by *2 mm. in width. Rays ’3 by 725 mm. Fragmentary 
specimens indicate much larger forms than the example figured. In the upper chalk 
examples of this form the rays are uniformly simple and more slender than in the 
greensand specimens. 
Acuate moniliform spicules (Plate 41, fig. 13), rarely occur in the same beds with 
the trifid forms, and, though much larger in size, they may have belonged to the 
same species with the trifid spicules. 
L. G. S., Haslemere, Godaiming. U. G. S., Warminster. 
28. Geodites planus (Plate 42, figs. 13-13c).—Zone spicules with slender, elongate, 
gradually tapering shafts, and simple or bifurcate head-rays, which extend nearly at 
right angles to the shaft. In some examples only two of the three head-rays are 
developed. Length ’875 to 172. mm.; width ‘062 to '125 mm. Rays '175 to '3 mm., 
by '05 to '09 mm. Very abundant. 
L. G. S., Haslemere. U. G. S., Blackdown, Haldon, Warminster, Merstbam. 
29. Geodites gracilis (Plate 42, figs. 12-12e).—Slender spicules, with straight 
tapering shafts, and short simple or bifurcate head-rays, which extend obliquely 
forwards. Length 1 to 17 mm. by ‘07 to '1 mm. Ptays '225 by '075 mm. 
U. G. S., Blackdown, Haldon, Warminster, Penzlewood, Merstham. 
30. Globate and globostellate spicides of the dermal layer of Geodites (Plate 43, figs. 
2-2 f ).—The spicules forming the dermal crust of this group of sponges are abundantly 
present. There are two varieties of globates; one is nearly spherical in form (fig. 2c), 
the surfaee smooth and apparently destitute of hilum. The average diameter is 
'233 mm. This form only occurs in the lower greensand at Haslemere. The other 
! variety is elliptical or reniform (figs. 2 a, 2 b, ), surface smooth, with a well-marked 
depression or hilum. The average size is 737 by '09 mm. It occurs in lower green¬ 
sand at Haslemere, Sevenoaks, Tilburstow Hill, and in upper greensand at Warminster, 
Blackdown, Merstham. 
One variety of globostellate is nearly spherical, 737 mm. in diameter, its surface is 
thickly covered with minute blunted elevations (fig. 2d). It occurs in the upper 
