271 ORISMOLOGY. 
14. Ensiform (Ensijbrmis). Whose horizontal sections 
are acute-angled triangles gradually diminishing 
in diameter from the base to the apex, and propa- 
gated in a straight line. Plate XL Fig. 7. 
15. Acinaciform (Acinacifonnis). Whose horizontal 
sections are acute-angled triangles gradually in- 
creasing in diameter from the base to the apex, and 
propagated in a curved line. 
16. Cultriform (Cullri/urinis). Whose horizontal sec- 
tions are equal acute-angled triangles, or a three- 
sided body with two equal sides large and the third 
small. 
17. Deltoid (Deltoidea). Short with the horizontal 
section triangular and decreasing in diameter to- 
wards the base. — Ex. Apex of the posterior tibia 
in Copris lunaris. 
18. Trigonal; Tetragonal; Pentagonal; Hexa- 
gonal; Polygonal {Trigona : Tetragona ; Pen- 
tagona ; Hexagona ; Polygona). Whose horizon- 
tal section is triangular; quadrangular; quinquan- 
gular; sexangular ; multiangular. 
19. Triedral; Tetraedral; Pentaedral; Hexa- 
edral ; Polyedral ( Triedra ,• Tetraedra ,• Pen- 
taedra ; Hexaedra ; Polyedra). That hath three 
sides \four sides \Jvoe sides; six sides ; many sides. 
20. Prismoidal (Prismoidalis). Having more than 
four sides and whose horizontal section is a poly- 
gon *. Plate VI. Fig. 13. «, &, d'. 
a The word employed in Botany to denote a Polygon is prismali- 
cat; but since, properly defined, this term is synonymous with trique- 
trous, we thought it best to use an adjective derived from prismoid, 
which implies a body that approaches to prismatical. 
