Messrs. Young on new Carboniferous Polyzoa. 335 



4, tho ccll-avcas arc of iinef|ual size and number on the two 

 faces. 



In Plate TX. the two faces arc sliown, and a transverse 

 section exliibitincj tlie proportions of the central axis. The 

 specimens are in the. Iluntcrian Museum. 



In the Exphmation of Sheet 23 (Mem. Geol. Survey Scot- 

 hmd) Mr. K. Etheridge, .Tun., refers (p. 102) to " a species of 

 l\'h/por(tj bearing a considerable resemblance to P. verrucosa^ 

 M'Coj. Tiie portions obtained are fragments of a robust 

 branching coralline, Avitli a nearly circular section, and a 

 generally strong and thick appearance, covered with numerous 

 cell-apertures arranged in alternating lines on the celluliferous 

 aspect, five or six apertures in each oblique line. The cells 

 are very pustulose or wart-like, with prominent raised margins. 

 The interspace between each aperture is occupied by waving 

 striai, and in some few specimens appears roughened. In 

 P. verrucosa, M'Coy, the apertures are round, in the present 

 species they are oval ; the margins are equal all round, here 

 one is more projecting than the other. It has also a more 

 robust and stronger appearance than McCoy's species. The 

 reverse presents the peculiar roughened look previously noticed. 

 As it has only, hitherto, been found in fragments, the general 

 habit and nature of the dissepiments cannot be stated. The 

 disposition of the cells and mode of branching are exceedingly 

 like those seen in Thamniscus duhius, Sclil. (King, Perm. Foss. 

 p. 45, pi. V. fig. 9). In the generic description of Pohjpora, 

 M'Coy (Synopsis Carb. Foss. p. 206) states that the margins 

 of the cell-apertures are never raised. As the margins in the 

 present form are decidedly raised and prominent, might it 

 not be a species of Thamniscus ? If it be a new species of 

 Polypora, I would propose for it the specific designation of 

 P. pustulataJ'^ 



We have received from Dr. Rankin, of Carluke, specimens 

 of the fossil in question, so well preserved and showing the 

 habit so clearly that we are enabled to give the following 

 description. 



Thamniscus'? Ranhini, sp. nov. Plate IX. his. 



Stems free, dichotoraous, circular, about -fV inch in diameter ; 

 branches in one plane. Celluliferous face equal to two thirds 

 of circumference. Cells arranged in spirals, the left-handed 

 series longer than the right-lianded. Cell-apertures circular 

 when entire, becoming oval when worn ; lower lip jjrominent ; 



