90 CARBONIFEROUS AND PERMIAN FORAMINIFERA. 



specimens are smaller than those from North America, but do not differ in any essential 

 character, as may be seen by comparing the drawings. 



VALVULINA RUDIS, nov., PI. Ill, figs. 19, 20. 



Characters. Test free or adherent, depressed, plano-convex. Exterior irregular, rough, 

 giving no evidence of internal structure ; margin thin. Interior doubtfully spiral ; habit 

 of growth obscured by the sub-division of the cavity into small irregular chamberlets. 

 Diameter -^5- inch (0'75 mm.). 



A less promising object for study than this obscure and rudimentary organism could 

 not easily be found. Time after time it was taken in hand, as specimens presented 

 themselves from various Carboniferous localities, with the conviction that it was an inde- 

 pendent species, before any clue to its structure or affinity could be traced. Specimens were 

 at length found of which it would be most correct to say that they were a little less devoid 

 of character than those previously met with. These seem to furnish tolerably clear indi- 

 cation of relationship to the genus Valvulina, though representing the lowest condition of 

 the type. They afford evidence of a sort of helicoid structure, the spiral band being very 

 broad and thin, and so confused with shelly ingrowths, dividing the cavity into small, 

 irregular, angular chamberlets, as to be traced with difficulty even under favorable con- 

 ditions. True septa there are none, their place being apparently served by labyrinthic 

 supplementary growths. The horizontal section commonly shows nothing but angular 

 cavities bounded by subarenaceous walls; cavities and walls being alike devoid of regu- 

 larity or order. In the dark coloured material, like the shales and earthly partings of our 

 English Carboniferous beds, this species is easily passed over without recognition, but in 

 the debris of the lighter coloured Fusulina-limestones it is more readily found. 



Distribution. In England Valvulina rudis has been met with in the Yoreclale rocks 

 only ; in Scotland at two localities of the Lower Limestone Group. I also have specimens 

 from the Fusulina-beds of Southern Iowa, N. A., and imperfect examples of what appears 

 to be the same form from Miatschkovo in Russia. 



Genus, ENDOTHYRA, Phillips. 



ENDOTIIYRA, Phillips, Segvenza, Brady. 

 UOTALIA, Ehrenberg, Hall, d'Eichwald. 

 NONIONINA (in part), d' Eichwald. 

 INVOLTJTJNA (in part), Brady. 



