SUPPLEMENT.— DUMORT I E R 1 A . clxxvii 



a series of species under the name striatulocostatus. 1 To one of these the present 

 species has much likeness, but it cannot be exactly identified therewith. The coil- 

 ing of the umbilicus does not correspond ; the ribs of the present species are more 

 pronounced, more approximate, and more persistent; and apparently the whole 

 shell is stouter. 



Locality a ml Stratum.— Gloucestershire : Penn Wood, near Stroud, in the 

 middle part of the Oephalopod Bed. 



Date of Existence. — Dumortieria hemera. 



11. Dumoiitieria externicostata (Branco). Plate XL, figs. 1, 2. Suppl., Fig. L69, 



p. cxcvi. 



1879. Harpoceras subundulatum, var. externe costatum, Branco, Unt. Dogger, 

 Abh. Geol. Spez. Karte Elsass-Lothringen, Bd. ii, PI. iii, fig. 3 only. 



1891. DUMORTIERIA STRIATULOCOSTATA, This MoUOgl'., PI. xl, figS. 1, 2. 



1902. externicostata, S. Buchma ii , Emend. Amm. Noin., p. 5. 



Note. — Smaller umbilicus and finer costation than D. striatulocostata, as now- 

 defined. 



12. DUMOETIEEIA MUTANS, 8. Hurkimi 11 . Plate XL, figs. 3 — 8. Suppl., Fig. 17<>, 



p. cxcvi. 



1891. Dumortieria striatulocostata, This Moiiogr., PI. xl, figs. 3 — 8, p. 243. 



Description. — Sublatumbilicate; costate declining to obscuricostate ; periphery 

 narrow, fastigate, parcicarinate. 



Distinction. — From Am. striatulocostatus, Quenstedt, 2 smaller umbilicus and 

 less coarsely costate. From Harp, externicostata, Branco, thinner, with earlier 

 degeneration of costae. 



13. Dumoetieeia DECLiNANS, S. BucJcman. Plate XL, tigs. 10—12. Suppl., Fig. 



171, p. cxcvi. 



1891. Dumortieria striatulocostata, This Mouogr., PL xl, figs. 10 — 12. 

 1902. declinans, Emend. Auim. Nom., p. 5. 



Descn^fa'ora— Sublatumbilicate ; subcostate declining to almost striate ; peri- 

 phery narrow, subtabulate, parvicarinate. 



1 Amm. Schwab. Jura, PL lii, fig. 7 ; taken as type, see this Monogr., p. 214. 



2 Amm. Schwiib. Jura, PL lii, fig. 7. 



Z 



