86 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



sutures form upon the umbilical slopes a series of curves, witli the concavities 

 directed forwards. Upon the peripheral area they sweep from side to side in a 

 broad and shallow backwardly directed sinus. Their distance apart is very slowly 

 augmented; where the transverse diameter of the peripheral area measures 

 30 mm. they are 7 mm. apart, this distance being increased to 10 mm. where the 

 diameter is 45 mm. It will thus be noticed that they are wider apart than those 

 of V. cariniferus, the form most nearly allied to the present one. There is a 

 well-marked annular lobe (PI. XXIII, fig. 4 c). 



The surface of the test is seen, even where it is somewhat eroded, to be 

 covered with fine, rather regular, transverse strise of growth, and on the portion 

 of the test preserved on the peripheral area, numerous faint, longitudinal striae 

 are visible, with here and there a backwardly directed sinus marking the form of 

 this part of the aperture. 



Affinities. — This species is very closely allied to V. cariniferus, J. de C. Sow., 

 the diiferences separating the two forms being the following : the peripheral area 

 is flatter and also broader than in V. cariniferus, the latter feature causing the 

 sides of the umbilicus to be steeper than in that species. The septa, as has been 

 shown, are wider apart in the present species than they are in Sowerby's ; hence it 

 seemed justifiable to give the former a distinct name. 



Remarks. — I am only acquainted at present with one specimen of this species, 

 but its characters are well marked, and its recognition will thus be readily secured 

 should other individuals be found. 



Locality. — Rathkeale, county of Limerick. 



Vkstinaotilus PAUcicARiNATus, A. E. FoonJ. Plate XXIV, figs. I — 5. 



1825. Nautilus multicaeinatvs, /. de C. Sotcerbi/. Min. Coiieli., vol. v, 



p. 129, pi. cccclxsxii, fig. 2 (excl. fig. 1). 

 1878. — CAEiNiFEiius, L. G. de Koninck. Faune Calc. Carb. Belgique 



(Ann. Mus. Roy. d'Hist. Nat. Belgique, 

 Paleont., torn, ii), pt. 1, p. 134, pi. xxviii, figs. 

 1 — 5 {not of J. de C. Sowerby). 

 1891. CffiLONAUTiLus PAUCICAEINATU8, A. U. Foord. Cat. Foss. Cepli. British 



Museum, pt. 2, p. 116, fig. 17. 

 1893. Vestinautilus paucicaeinatus, A. Hyatt. Carboniferous Cephalopods. 



Second paper. Geological Survey of 

 Texas, Fourth Annual Report, 1892, 

 p. 420. 



Description. — Shell thick-discoid, composed of three volutions which increase 

 rapidly in diameter and are exposed in a deep, funnel-shaped umbilicus, having a 



