SUPPLEMENT.— LUDW1GI. 



lxix 



of the Building Stone; Horn Park, near Beaminster, in an ironshot matrix, which 

 is really the same bed. 



Date of Existence. — Bradfordensis bemera. 



XXIV. Genus — Ludwigia, Bayle. 

 (Type — Ludwigia Murchisonse, Sow., sp.) 

 1S87. Ludwigia, This Monogr., p. 1G (pars). 



Definition. — Platy-subleptogyral, subangustumbilicate ; sub- 

 pauciseptate, longi-angustilobate ; laterally anguliradiate ; peri- 

 pherally latanguliradiate, subtabulate, parvi-nonsepti-carinate. 



Distinction. — From Kiliania, radial line, with more lateral bend ; 

 mode of growth, greater umbilication with greater compression ; from 

 Paquieria persistence of costge, suture-line; from Wiltshireia, suture- 

 line ; from Welschia and Cosmogyria, radial line and mode of growth. 



Remarks. — Bayle selected Am. Murchisonse as the type of his 'lin'eof " 

 genus Ludwigia, but what he figured by that name did not agree MurcHsolx. 

 with Sowerby's type example. That was pointed out in the body of this work, 

 though the matter did not seem of so much importance as at present. How- 

 ever, it was then decided to recognise Sowerby's and not Bayle's Murchisonse as 

 the type of the genus, and it is undesirable to alter that arrangement. Still it 

 is doubtful whether any of Bayle's " Murchisonse" belong to the genus Ludwigia 

 as now defined : one has some similarity but differs in septation. (See Ludwigia 

 gradata, p. lxxi ) 



), 



1 . Ludwigia tubeiiculata, S. Buclcman. Plate III, figs. 4, 5 ; Plate A, fig. 2 ; Suppl. 



Plate XI, fie,. 30. 



1SS/ 



Ludwioia Murchisonse, var. obtup.a, This Monogr. 



PL a, fig. 2. 



PI. 



Ig8. -I, 5 : 



Description. — Subplaty-subpachygyral, sublatumbilicate; bullati-costate. 



Note, — The bullae are somewhat irregularly developed. 



Distinction. — From Hi/attia bullifera, a smaller umbilicus. 



Localities and Strata. — Dorset : Beaminster, towards the base of the " Inferior 

 Oolite" limestone. Another specimen unlocalised, probably from Haselbury, 

 Somerset, and certainly from the horizon of Zeilleria anglica, for there is ;ni 

 example thereof in the matrix. 



Date of Existence. — MurcliisoncC hemera. 



