SUPPLEMENT. -DUMORTIERIA. clxxxiii 



Description. — Subexcentrumbilicate ; striate (a small costate stage in inner 

 whorls); periphery fastigate, parcicarinate. 



Distinction. — From D. Moorei, the earlier loss of costse and the peculiar 



umbilicus. 



Remarks. — This species seems to have great likeness to the Chili fossil figured 

 by Bayle and Coquand; but in face of what is known about homoeomorphy it 

 would be hazardous to suggest identity. 



Plate XXX, u 

 p. cxcvi. 



1890. Dumortieria Moorei, Tliis Monogr., PL xxx, figs. 15 — 17. 



Description. — Subplatyleptogyral, sublatumbilicate, with definite inner margin; 

 striate ; periphery fastigate, parvicarinate. 



Distinction. — From D. Mooeei, the want of a costate stage; the definite inner 

 margin (Lycett says of his species " inner border of whorls not truncated," p. 122). 

 From D. subexcentrica, the want of costa) in the umbilicus, the more definite peri- 

 phery and carina. 



Localities and Strata. — -Dorset: Bradford Abbas, Yeovil Sands, upper part; 

 Chideock Quarry Hill, Bridport Sands— specimens at a fossiliferous horizon 50 feet 

 from top of sands and from where opalinoid Ammonites occur, 110 feet from base 

 of sands, and 180 feet from first appearance of Dumortieriae in so-called Upper 

 Lias clay. 



The strata on Dorset coast (sands and clay) which yield Dumortieriae are about 

 200 feet in thickness. 



Date of Existence. — Moorei hemera. 



2'.). Dumoktieiua sp. Plate XLIV, figs. 4—6. Suppl., Fig. 182, p. cxcvi. 



1891. Dumortieria Moorei, This Monogr., PI. xliv, figs. 4 — 6. 



Remarks. — This form lacks the costate umbilicus of D. Moorei, the excentnun- 

 bilicus of D. subexcentrica ; the definite inner margin of l>. Huron's. It has also a 

 less definite periphery than the typical P. linearis, a slightly larger umbilicus, and 

 is thinner. 



Widely umbilicate species. 

 Compare with D. subsolaris for the costate ally. 



30. Dumobtieeia lata, 8. Buckman. Plate XLIV, figs. 1—3. Suppl. fig. L83,p.cxcvi. 



1885. Ammonites cf. radians, Quenstedt, Ainui. Schwab. Jura, PI. liv, tig. 19. 

 1891. Dumortieria uadians, var. exigua, This Monogr., PI. xliv, figs. 1 -3 only. 



