c) (MS. B. 96b, see p. 45 Fig. 2). Octagon with an aisle round it;
the angles of both are formed by columns. The outer sides are formed
by 8 niches forming chapels. The exterior is likewise octagonal,
with the angles corresponding to the centre of each of the interior
chapels.

Pl. XCII, No. 2 (MS. B. 96b). Detail and modification of the
preceding plan--half columns against piers--an arrangement by which
the chapels of the aisle have the same width of opening as the inner
arches between the half columns. Underneath this sketch the
following note occurs:_ questo vole - avere 12 facce - co 12
tabernaculi - come - _a_ - _b_. _(This will have twelve sides with
twelve tabernacles as_ a b._) In the remaining sketches of this
class the octagon is not formed by columns at the angles.

The simplest type shows a niche in the middle of each side and is
repeated on several sheets, viz: MS. B 3; MS. C.A. 354b (see Pl.
LXXXIV, No. 11) and MS. Ash II 6b; (see Pl. LXXXV, No. 9 and the
elevations No. 8; Pl. XCII, No. 3; MS. B. 4b [not reproduced here]
and Pl. LXXXIV, No. 2)._

_Pl. XCII, 3 (MS. B, 56b) corresponds to a plan like the one in MS.
B 35a, in which the niches would be visible outside or, as in the
following sketch, with the addition of a niche in the middle of each
chapel.

Pl. XC, No. 6. The niches themselves are surrounded by smaller
niches (see also No. 1 on the same plate).