MANUAL OF THE MOLLUSCA. 
6. CERATITES (see p. 197). 
Division I1.—SuUTURES FOLIATED 
Including the genera Ammonites (p. 197), Toxoceras, Ancylo- 
ceras,* Scaphites, Helicoceras, and Turrilites (p. 200), Hamites, 
Ptychoceras, and Baculites (p. 201), and the following. 
ANISOCERAS (see p. 200), Pictet, 1854. 
Etymology, anisos, unequal; and ceras. 
Example, Hamites armatus, Sowerby. 
- Shell at first growing in an open helicoid spire, afterwards 
more or less prolonged and reflected; ornamented by trans- 
verse ribs. Sutures of septa divided into 5 lobes and 5 saddles, 
all bipartite ; the lateral saddles are the largest. 
Fossil, 12 species. Gault—Upper Green Sand, Europe. Cre- 
taceous, India. 1 species, Jurassic. North-west Himalayas. 
Species of Helioceres founded on helicoid portions of shells 
may belong to this genus. 
HAMULINA (see p. 201), D’Orbigny, 1852. 
Example, H. dissimilis, D’Orb. 
Shell conical prolonged, having a portion of the body chamber 
reflected, but not touching the other portion; section of the 
shell round or laterally compressed; sutures of the septa 
divided into six lobes, and as many saddles. 
Hamulina differs from Hamites in being only once reflected 
mstead of twice, and from Ptychoceras in having the reflected 
portion of the shell separate from the other, not close together. 
Distribution, 15 species. Neocomian, France. Ootatoor 
group (= P Gault), India. 
PELTARION, Deslongchamps, 1859. 
Founded on the mandibular armature of tetrabranchiate 
cephalopods 
* Many of the forms considered to belong to Crioceras have been ascertained 
by M. Astier to be only more or less incomplete individuals of species belonging te 
Ancyloceras. That Crioceras must merge into Ancyloceras appears inevitable. 
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