SUPPLEMENT.— DENCKMANNIA. xix 



2. Denckmannia tumefacta, S. Bucbman, Suppl., Plate I, figs. 7 — 10. 



Description.— Stenopachygyral, sublatumbilicate, subirregulari-crassornate, 

 bullate, versi-recticostate, septicarinate, subpauciseptate. 



Note. — The carina is strong and laterally compressed. On the core of the 

 periphery are slight signs of furrows. The tubercles are elongated in the 

 direction of the ribs, and are therefore technically bulla?. The ornamentation is 

 somewhat irregular. 



Distinction. — This species is like the erbaensis of Dumortier (non Hauer),butit 

 is distinguished by the difference in direction of the costa?. It is also less 

 umbilicate and more quickly coiled. It is less umbilicate and yet thicker than 

 robustns, Denckmann. 



Locality and Stratum. — Somerset : Shepton Beauchamp, just above where 

 Hildoceras bifrons is plentiful. 



Date of Existence. — Lilli hemera, presumably, — that is to say, it was probably 

 earlier in date than variabilis, and later than bifrons ; but the strata being very 

 thin, it lies closely associated with them. 



3. Denckmannia torquata, S. Bud-man. Suppl., Plate III, figs. 4 — 6. 



Description. — Platygyral, angustumbilicate, crassornate, bullate, subrursi-flexi- 

 costate, 1 septicarinate, subdensiseptate, L. broad. 2 



Note. — The umbilicus tends to become excentric, while the costa? and bulla? 

 are retained. The rursi-flexicostate character becomes more pronounced with 

 age. 



Distinction. — The much thicker form, and the more rounded, broader periphery 

 separate it from Haugia illustris (Denckm.). The combination of coarse orna- 

 mentation with a small excentric umbilicus and rather thick whorls (relatively to 

 similarly umbilicate species) is the distinctive character of the present species. 



Remarks. — The retention of the bulla? and the strong character of the ribbing, 

 in connection with a compressed form and a small umbilicus, indicate a possible 

 connection with Denckmannia tumefacta. In the same direction does the some- 

 what small carina point. The subrursi-flexicostate character seems to be only a 

 later acquirement, and is not necessarily against such connection. 



Locality and Stratum. — Shepton Beauchamp, Somerset, with species of Haugia, 

 above Hildoceras bifrons. 



Date of Existence. — Variabilis hemera. 



1 In the latter part of the whorl. 



2 L. = superior lateral lobe. 



