256 
THE LIAS AMMONITES. 
(fig. 170). I have collected magnificent examples of this grand form, occuring in 
nodules, from eighteen inches to two feet long, in the Lower Greensand at Whales Chine, 
Fig. 170. — Scaphites gigas, Sowerljy. 
near Black-Gang, Isle of Wight. ScapJdtes Ivanii, Puzos (fig. 169), is from the Lower 
Neocomian ; and Scaphites aqualis, Sow., is found in the Lower Chalk at Lewes, Sussex, 
and Chardstock, Somerset. 
Genus Hoplites, Neum. — This genus is composed of a series of species formerly 
classed among PerispJiinctes, but- now separated as a new genus, characterised by 
having the shell closely involute, with high whorls and a narrow umbilicus. Sculpture 
consists of numerous small undulating ribs, often polytomate (fig. 171), that is, arising, 
by a thickened stem or tubercle, from near the umbilical suture, and soon splitting up into 
smaller divisions ; sometimes the ribs encircle the siphonal area, or are interrupted here 
either by their vanishing away at the border of the area, or by a median channel, which 
breaks their continuity, or by a kind of crest formed by the abrupt termination 
Fig. in. Fig. 172. 
Hoplites falcatus, Mantell. Hoplites Beaumontianus, d'Orb. 
of the lateral ribs, as in HopL splendens, Sow. ; or the lateral ribs may be folded and 
angular, as in Hopl. falcatus, Mant., or large and powerful, as in HopL interruptus, 
Brug. There is a considerable variety in the style of the rib-sculpture and the form it 
