PLATE X. 
Aster. stellare.1 Fig. 1, 2, drawn from a sketch of a specimen in the Museum of Stutt- 
gardt, 450 mm. in diameter, showing extreme modifications in old age, loc. Géppingen. 
Aster. acceleratum. Fig. 3, drawn from sketch of specimen in Museum of Stuttgardt, 
258 mm. in diameter, showing premature senility, loc. Balingen. 
Oxyn. oxynotum. Fig. 4, 5, young of striaries-like variety, magnified twelve times, loc. 
Balingen. 
Ast.impendens. Fig. 6, young magnified four diameters. Fig. 7, abdominal view of 
same, showing the early age at which the convergent sides, deep channels, and prominent keel 
are developed. Fig. 8, 9, older stage of same specimens. Loc, Semur. 
Aster. Collenoti2 Fig. 10, full-grown specimen, natural size, showing ribbed young, loc. 
Champlony, near Semur. 
Agass. Scipionianum.’ Fig. 11, 12, var. spinaries of Quenstedt, loc. Gmiind. Fig. 13, 
older specimen of same variety, with more compressed whorls and less prominent tubercles, loc. 
Semur. 
Oxyn. oxynotum. Fig. 14, abdominal view of young with part of whorl removed, mag- 
nified three diameters. Fig. 15, same specimen when whole. Loc. Balingen. Fig. 16, young 
with prominent pile and keel, loc. Gloucester. Fig. 17, young in the Museum of Stuttgardt, 
showing absence of the keel until a late stage of growth, and exhibiting similarity to the 
adult of Agass. levigatum and striaries. Fig. 17 a, suture of same enlarged. Fig. 18, ordinary 
aspect of the young. Fig. 19, pathological case with crenulated abdomen, like the margaritatus 
forms. Fig. 20, young of a variety, with folds on the abdomen. Loc. Balingen. Fig. 21, 22, 
adult, loc, Salins. 
Oxyn. Lotharingum. Fig. 23-26, showing solid keel in young, hollow keel in adult, 
and partly obsolescent keel in old age of specimen in Museum at Semur. 
Oxyn: oxynotum. Fig. 27, showing hollow keel filled with layers of shell in specimen at 
Museum of Semur. 
Oxyn. Guibali. Fig. 28, 29, 31, drawn from sketch of specimen in the Museum of Semur, 
showing solid keel in young, hollow keel in adult, and absence of keel in old age. 
Oxyn. Greenoughi. Fig. 30, enlarged perfect specimen of hollow keel in adult, loc. 
Stuttgardt. 
1 See Plate IX. Fig. 2, 3. 2 See Plate IX. Fig. 10, 11. 
3 See Plate VII. Fig. 11-15. 
