Figs. 1-6,—Hyolithus (Orthotheca) fistula (Holl). From the grey 7 
Hollybush Sandstone of Raggedstone Hill. 
i) (<3 diam.) 3. (X8 diam.) 4. (x4 diam.) 
2. (x8 diam.) 
5. (x16 diam.) 
6. (x14 diam.) ae 
& 
Fig. 1.—Vragment of tube measuring 2 mm. in diameter; fig. 2, transverse 
: section of the same. 
3.—Fragment of a gently tapering tube, showing transverse striz. 
4,—-Fragment of a slender tube, the greater part of which is represented 
by an external cast. Doubtfully referred to Hyolithus fistula, 
possibly belonging to Hyolithellus or to Coleoloides. 
Figs. 5 & 6.—Transverse sections of two tubes of A. fistula, to show the 
variation in shape. 
