THE CEPHALOPODA. 
195 
canal. Septa formed of lobes and saddles divided into single parts. Sipbonal lobe 
shorter than the superior lateral lobe. Hoplites falcatus, Mantel) (fig. 76), from the 
Chalk Marl, and II. auritus, Sow., from the Gaiilt, are good types of Tuberculati. 
Fig. 76. — Hoplites falcatus, Mantell. Fig. 77. — Schloenhachia Goupiliana, d'Orb. 
c. Species with the siphonal area trenchant without forming a keel. 
5th Section. Clypeiformi, d' Orhigny. Shell compressed, generally smooth or little 
ornamented with undulating folds or radii. Siphonal area sharply bevelled, without a keel. 
Spire writh large whorls mostly much involuted. Septa divided into a great number of 
lobes formed of single parts, and of saddles partly in pairs and partly single. Siphonal 
lobe shorter than the superior lateral lobe ; the saddles and the lobes large and short. 
S. Goupiliana, d'Orb. (fig. 77), from the Upper Greensand, is a good type of this section. 
d. Species with the siphonal area prominent and crenulated on the median line. 
6th Section. Amalthei, von Buch. See page 188. 
7th Section. Pulchelli, d'' Orhigny. Shell elegantly divided on the sides by promi- 
nent ribs, straight and not flexed, which passing from one side to the other leave upon 
Fig. 78. — Hoplites Brottianus, d'Orb. 
Fig. 79. — Hoplites Beveriantcs, d'Orb. 
