SUPPLEMENT.— (ECOTRAUSTES. cxcv 



feeble on inner area; periphery subfastigate to convex, carina small to nearly 

 obsolete. 



Note. — The plain costate stage until 33 mm. diameter ; stage with novate -en (led 

 costae to 39 mm. diameter; then relapse to plain costate stage. 

 There are three stages in last whorl : 



( 1 ) Costate, with nearly straight radial line. 



(2) Nodate, costae ending in blunt knobs near carina ; radial line much 

 curved. 



(3) Post-nodate, the knobs have gone, the costae are declining. 



Stages 1, 2 are carinate; in stage 3 the periphery is rounded, the whorl swollen, 

 the inner margin receding from centre. 



Distinction. — From Oec. rugosus, the smaller costae, the umbilicus, and the 

 general proportions. 



Locality and Stratum. — Dorset : Bradford Abbas, from the White Beds. 



Date of Existence. — Probably hemera fuscse. 



(Ecotraustes nodiper, 8. Buchman. Plate XX, figs. 13, 14. Suppl., Fig. 191, p. cxcvi. 



1889. (Ecotraustes conjungens, This Monogr., PI. xx, figs. 13, 14. 



A ixl compare 

 1869. Oecotraustes conjungens, Waagen (non Mayer), Formenreihe Am. subra- 



diatus, Geol. Pal. Beitriige, Bd. ii, Heft ii, 

 PI. xx, fig. 5. 



Description. — Platygyral ; excentrumbilicate ; semicostate, the inner area nearly 

 smooth ; nodi when developed, strong ; periphery subfastigate, parvicarinate. 



Note. — Plain costate stage to 27 mm. diameter ; then follows the stage with 

 costae ending in nodi. 



Distinction, — From Am. conjungens, Mayer, 1 smaller umbilicus, more distinct 

 ornament, more definite carina. From Oec. costiger, the smooth inner area, the 

 greater excentricity of umbilicus, the more definite carina and nodi on the peri- 

 phery. 



Localities and Strata, — Dorset : Bradford Abbas, from the White Beds ; Burton 

 Bradstock, from the Upper Beds. 



Date of Existence. — Probably hemera fuscse. 



1 ' Journ. Conchyliologie,' vol. xiii, PI. viii, fig. 6, p. 322, 1865. 



