PLATE XCI. 
Concavum-zone. 
Figs. 1—3.—Sonninta quapriripa, 8S. Buckman. 
Fig. 1.—Side view reduced to one-half the natural size. Much of the test is 
absent from the last whorl. Bradford Abbas, Dorset. My Collection. (Page 
366.) 
Fig. 1a.—The last part of the outer whorl of the other side, showing the 
increase in the size of the ribs. In Fig. 1 this is lost, owing to the breakage. 
Reduced to one-half. 
Fig. 2.—Outline of the front view, reduced to one-half (a—a). 
Fig. 3.—Septa showing superior lateral lobe, with isosceloid, axial terminal 
lobule, and with nearly equipoised, bipartite lateral lobules. 
Figs. 4—6.—Sonninia mutans, S. Buckman. 
Fig. 4.—Side view—reduced to one-half of natural size—showing a spinous 
stage persistent to the last half-whorl, which is body-chamber. Bradford Abbas. 
My Collection. 
Fig. 5.—Outline of the front view, reduced to one-half (b—D). 
Fig. 6.—Septa showing the superior lateral lobe with anisosceloid terminal 
lobule. 
Figs. 7—9.—Sonninta pavcinopata, S. Buckman. 
Fig. 7.—Side view, reduced to one-half of naturalsize. Bradford Abbas. My 
Collection. (Page 370.) 
Fig. 8.—Outline of the front view similarly reduced (c—c). (The inner margin 
is not sloped enough. It forms with the side an angle of about 120°, and an 
inner angle 55° with the sagittal line. The indentation is also hardly sufficient, 
and the ventral convergence is too pronounced.) 
Fig. 9.—Septa showing superior lateral lobes with anisosceloid, intra-axial 
terminal lobules. 
