PLATE III.* 
I, 2, 3. Lituites Giganteus. ( Gigantic Lituites.) About three ratlier compressed wliorls; 
surface, with numerous, transverse, arcuated ribs, obsolete over margin; aperture somewhat quad¬ 
rangular, with rounded corners; siphuncle nearly central. Diameter of last whorl in., length of 
aperture If in. Fig. 2 represents a section ; and Fig. 3, a portion of back. 
4, 5. Clymenia Linearis. ( Lined Clymenia.) Inner whorls discoidal, convolute; back with 
smooth, narrow, central keel; section of whorl elliptical, oblong, impressed by inner whorl; siphuncle 
small; surface, with gently bent, transverse striae; septa obsolete. 
6. Actinoceras Simmsii. ( Simm’s Adinoceras.) Shell large, conical; upper chamber very 
deep; siphuncle large, continuous, contracted at attachments ; septa composed of several laminrn and 
rather thick. Length about 2 ft. 
7,8,9. Cyrtoceras Nautiloideum. ( Nautilus-shaped Cyrtoceras.) Involute, tapering; sec¬ 
tion nearly circular; septa slightly oblique; siphuncle near back, almost half way from centre 
towards convex line of shell. Fig. 8, chamber of 0. marginale seen on face; fig. 9, ditto on edge. 
10. Gomphoceras Pyriforme. ( Pear-shaped Gomphoceras.) Ovate, pear-shaped, with 
chambered portion elongated; septa numerous, even ; siphuncle largish, half way between centre 
and margin, and inflated between septa; aperture narrow; surfaces smooth. Length of inflated 
portion 4 in., diameter of ditto 2^ in. 
II. Phragmoceras Ventricosum. (. Bellied Phragmoceras.) Compressed, slightly arcuated, 
somewhat hooked near apex; aperture nearly closed in middle; beak produced ; surface, with many 
ridges, crossing edges of numerous septa. 
12, 13. Crioceras Bowerbankii. (Bowerbarik’s Qrioceras.) Four whorls, slightly flattened 
on sides and nearly close; inner ones, with numerous, radiating sulci, which, disappearing upon outer 
whorl, are succeeded by eight or ten thick, arcuated ribs, extending across whorl; aperture thinly 
edged and transversely oblong. Diameter 7\ in., breadth of aperture 2f in. 
( 4 ) 
