94 
VINE: NOTES ON YOREDALE POLYZOA. 
round to slightly hexagonal, and tuberculated on the ridg-es. The 
inner portion of the vestibule slope away from the ridges 
towards a small circular or eliptical cell orifice. A similar feature 
is noticible in that of Rhomhojjora elegantula, Ulrich, Jour. Cincin. 
Soc. Nat. Hist., April, 1884, p. 33), but the mode of branching 
in the British species is more like that of Anisotryjja symmetrica, 
Ul. (Op. cit., Dec, 1883, p. 176, pi. XIIL, fig. 5). The branches 
of the Hurst and Lancashire specimens are not quite so large as the 
American. 
Horizon and Localities : Yoredale ; North Lancas., Hurst, W. 
Yorks. 
29. RlIOMBOPORA VmnULAlUFOKMlS, n. sp. PI. X., fig. 10. 
Size of Zoarium and mode of blanching unknown. Stem very 
delicate, or in some specimens rather robust. Zoaicial apertures 
slightly prominent; vestibule eliptical ; cells arrang'ed in lines, with 
their posterior ends elongated. On both sides of all the linear 
series of cells there are undulating l ows of tubercles. 
Localiti/ : Yoredale ; Gleaston Castle. 
This delicate little form ma}' have been previously noticed by 
authors even if not fully described. M'Coy's Vincularia megastojiie 
has a similar arrangement of cells, but I believe that he has not 
described the ornamentation in his species. Mr. John Young, 
however, has examples of a similar form to the North Lancashire 
species described above, which he has named (provisionally ?) 
V. megastonia, M'Coy, the locality of which he gives as Brockley, 
near Lesmahagow. 
30. RiiOMBOPORA sp. 
There are present in the North Lancashire, Northumberland, 
and also in the Hurst Shales, several fragments of species of 
jRliomhopora, more allied to American than to any British forms. 
These will merit further study, and as there are difficulties to be 
overcome when we have to rely on external features only, I shall 
not be blamed. I hope, if for the present I withhold special details. 
1 felt that it was necessary to make reference to these, otherwise, 
students of Carboniferous Polyzoa may detect undescribed fragments 
and be puzzled respecting them. 
