SUPPLEMENT.— LUDWIGINA. 



lxi 



XIX. Genus — Ludwigina, 8. Bnchnan. 



(Type — Ludwigina pattila, sp. n.). 



1887. Ludwigia (pars), This Monogr., p. 16. 



Definition. — Substeno-leptogyral, latumbiiicate ; pauciseptate, sub- 

 longi-subangustilobate ; laterally flexiradiate ; peripherally auguli- 

 radiate, subtabulate, parvi-nonsepti-carinate. 



Distinction. — Similar to Apedogyria, but more umbilicate. 



Remarks. — The radial curves in this and the last genus are practi- 

 cally the same. But Ludwigina patula and Apedogyria patellaria are FlG- }?;~f ;ld 

 in the same degree of development. The degree of costation and Lwdmgina 

 compression is similar, but the umbilicus associated therewith is much 

 larger in the present genus. 



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1. Ludwigina patula, S. Bud-man. Plate III, fig. 3 ; Suppl., Plate XIV, 



figs. 7, 8. 



1887. Ludwigia MuiicinsoKJD, This Monogr., PI. iii, fig. 3 only. 



Description. — Substenoleptogyral, latumbiiicate ; costate. 



Localities and Strata. — Dorset: Louse Hill, near Halfway House; Bradford 

 Abbas, in the Paving Bed; Marston Road, near Sherborne, probably from below 

 the ringens horizon. 



Date of Existence. — Murchisonse hemera. 



2. Ludwigina umbilioata, S. Buckman. Woodcut Eig. 18 in text. 



Description. — Subplaty-leptogyral, latumbiii- 

 cate ; subparvicostate. 



Distinction. — From patula, less coarse costa- 

 tion, smaller umbilicus, greater compression. And 

 the small patula (Suppl., Plate XIV, figs. 7, 8) shows 

 rather more angustilobation than Fig. 18, c. 



Locality and Stratum. — Dorset: Bradford Abbas, 

 in the Paving Bed. 



Date of Existence. — Murchisonas hemera. 



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1" i < ; . L8. — Ludwigina umbilicata. 

 side view ; h, section ; c, suture-line ; 

 rf, radial liue. 



