112 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



those who are interested in the matter to consider this as a temporary act on my 

 part, and one which is subject to revision should occasion require it. 



The differences between the present species and P. oxijstomum may, indeed, be 

 taken in at a glance (cf. PI. XXVIII, figs. 3 a, h). The stout form and 

 remarkably straight sutures of the one are in marked contrast with the curved 

 sutures and extremely attenuated habit of the other. The resemblance between 

 them is reduced, in fact, so far as the outer whorl is concerned, to the common 

 feature of an acute periphery. 



BemarJcs. — In dealing with this new form two courses were open to me ; one 

 was to found a new genus for its reception, the other to merge it in one already 

 known. I have chosen the latter alternative, because there is but a single 

 individual, and its condition is such as to preclude the possibility of investigating 

 the important characters which are afforded by the initial whorls, owing to their 

 being partly destroyed, partly hidden by the matrix filling the umbilical 

 depression. It must be left, therefore, to further research to supply this 

 deficiency. Meanwhile the above description will serve to distinguish the fossil, 

 and by its imperfect character draw attention to the fact that more information 

 regarding it is a desideratum. 



I am glad of this opportunity to express my indebtedness to Mr. Gr. H. 

 Elliott, the Chief Librarian of the Free Public Library, Belfast, for kindly 

 affording me every facility to examine and figure the specimen described above. 

 It is contained in the collection of fossils made by the late Canon Grainger, D.D., 

 M.R.I.A., of Belfast, who presented his large collections (ethnological, zoological, 

 geological, etc.) to the institution just named, where they are under careful 

 curatorship and are fully accessible to students. 



Localltij. — There is, unfortunately, no record, but as nearly all the fossils in 

 the Grainger Collection came from Kildare, the chances are greatly in favour of 

 the one here described having been obtained in that county. 



[Vestinautilus cariniperus, J. de G. Soirerhy, var. tripUcatus, var. nov. Plate 



XXVIII, figs. 2 a, b. (See supra, p. 82.) 



The very strong folds near the aperture (much too obscurely rendered in the 

 figures) is so marked a feature in this individual, the only one known to me, that 

 it demands particular notice. Only three folds are to be distinguished, the outer 

 one of which bridges over the space extending from the edge of the umbilical keel 

 to that of the aperture ; this fold is flattened and rather inconspicuous. The 



