22 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



Affinities. — A species named by de Koninck 1 Orthoceras vicinale, of which 

 only part of the body-chamber was known to the author, came under my 

 notice at Brussels. A comparison with the Irish form showed a general 

 similarity in the ornamentation, but as this is the only character available 

 for comparison I do not feel justified in uniting the two forms upon this 

 ground alone. De Koninck's Orthoceras Morrisianum, which that author 

 describes from specimens found at Vise, Belgium, and alleges to have been found 

 at Rathgillen and Kilgrogan in the county of Limerick, has an ornamentation 

 consisting of very fine thread-like lines, about their own width apart, and which 

 towards the anterior part of the body-chamber divide into two or three finer lines 

 between coarser ones. These are manifestly different from the imbricating lines 

 ornamenting the shell of Orthoceras Glanense. The two species are also dis- 

 tinguished by the position of the siphuncle and the direction of the sutures, 

 oblique in 0. Glanense, horizontal in 0. Morrisianum. I examined a specimen of 

 the latter in the Brussels Museum, and I think I recognise this species in a 

 fragment in the Museum of Science and Art, Dublin, from Kilgrogan (Limerick), 

 whence Baily's figured specimen named Orthoceras cinctum 2 came. The latter, 

 drawn in a very sketchy manner, is not described, and I have not been able to 

 find the original. The figure, however, indicates a form with a slower rate of 

 increase and much closer septa than Orthoceras Glanense has. It may possibly 

 be referable to 0. Morrisianum. 



Remarks. — This fine species will recall some similar forms figured by Barrande 

 (' Syst. Sil. de la Boheme'). The ornamentation makes it easily recognisable. 

 It is not very rare in the Clane quarries, but I have not met with it anywhere 

 else. 



Locality. — Clane, county of Kildare. 



1 ' Faune Calc. Carb. Belgique ' (' Ana. Mus. Koy. d'Hist. Nat. Belgique, ser. Paleont.,' vol. v), 

 pt. ii, p. 69, pi. xlv, figs. 3, 3 a, 3 b. 



2 ' Figures Char. Brit. Foss.,' vol. i, Palaeozoic, 1867-75, pi. xl, figs. 8 a, 8 b. 



