PLATE XXVII. 



N.B. — About half the figures are drawn from photographs, more or less enlarged. 



Fig. 

 la, lb. Onustus pyramidatus, Phillips. Wide-angled variety with straight ribs. 



From (?) Murchisonge-zone, Chideock. My Collection. Front and 



base X 1J. (Page 326.) 

 2 a, 2 b. The same. Specimen believed to be the type, Dogger ; Blue Wyke. 



York Museum. Back and base X 1^. 

 3. Onustus acuminatus, sp. nov. Murchisonge-zone, North Dorset. Whidborne 



Collection. Back X 1£. (Page 328.) 



4 a, 4 6. Onustus heliacus,6V 'Orb., var. opalina. Op alinus -zone, Drympton. My 



Collection. Front and base X H- (Page 329.) 



5 a, 5 b. Onustus cf. lamellosus, d'Orbigny. (The base shows a deeply excavated 



umbilicus as in d'Orbigny's figure, but the radial ornaments are 

 wanting). Concavus-bed, Bradford Abbas. My Collection. Front 

 and base X 1\. (Page 328.) 



6 a, 6 b. Onustus Heberti, Laube. Stoford. ? Parhinsoni-zone. My Collection. 



Front and base X 2. (Page 329.) 

 7. The same. Wide-angled variety, with the spirals in the base and the 

 crenulations of the margin more strongly developed. Gad omen sis -bed, 

 Oborne. My Collection. Base X 2. 



8 a, 8 b. Onustus ornatissimus, d'Orbigny. Parhinsoni-zone, Burton Bradstock. 



My Collection. Front and base X 1£. (Page 330.) 



9 a, 9 b, 9 c. Neritopsis Bajocensis, d'Orbigny. Parkisoni-zone, Burton Brad- 



stock. My Collection (Stephens). Front, back, and apex X 1£. 

 (Page 340.) 



10. Operculum of Neritopsis Bajocensis, d'Orb. Humphriesianus-zone, Sherborne 

 district. My Collection (Stephens). In position, natural size. 



11a, 116, lie. Neritopsis Philea, d'Orbigny, Inferior Oolite variety. Concavus- 

 bed, Bradford Abbas. My Collection. Front, back, and apex X 1\. 

 (Page 341.) 





