PLATE III. 
Arn. Hartmanni.' Fig. 1,1, cast. Fig. 1 shows the thick shell lying on the keel of 
the cast. Loc. Lyme Regis. 
Cor. kridion. Fig.2, young. Fig. 2a, outline of young suture of Fig. 2, enlarged. Fig. 3, 
cast. The last volution in this represents the living chamber. Loc. Balingen. 
Cor. rotiforme, var. A. Fig. 4-4a, young smooth stage and suture. Fig. 5, 6, 8, 8a—10, 
10a, older stages of same. Fig. 7, 11-13, pathological cases with pile crossing the abdomen. 
Loc. Semur. Fig. 14, 15, 15a, 16, kridion-like variety of this species. (Fig. 14, loc. Stuttgardt ; 
Fig. 15, 16, loc. Balingen.) Fig. 17, 17 a, variety with discoidal form and large tubercles, figure 
reduced to about two thirds, loc. Semur. Fig. 17 b, sutures. 
Cor. Bucklandi, var. sinemuriense. Fig. 18, figure reduced to less than one half, show- 
ing the divided pile of the young (sinemuriense stage), and the solid Bucklandian pile of the 
adult, loc. Semur. 
Cor. latum. Fig. 19, young with narrow abdomen. Fig. 22, older stages of same variety, 
showing affinities for Cor. rotiforme and Bucklandi. Fig. 20, section of young of variety with 
broader abdomen. Fig. 21, 23, 23a, older stages and suture of same. Loc. Semur.? 
1 See Plate II. Fig. 17. 
2 These specimens all appear to be in the nealogic stages of development. 
