12 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



shells ; but in the absence of a gi-adational series from young to adult this point 

 would be very difficult to determine. In the present case, at least, I have not 

 been able to identify the form above described with any of the larger species in 

 their young stage of growth, hence there was no alternative but to regard it as a 

 distinct species. 



Locality. — St. Doulagh's, near Dublin. 



SuB-GKOUP MonHiformes {sijjhuncle moniliform). 



Okthoceuas Hindei, a. H. Foord. Plate V, figs. 4 a — c. 



1S96. OuTHOCEEAS HiXDEi, A. R. Foord. Ueber die Orthoceren des Kohleu- 

 kalks (Carboniferous Limestone) von Irland. 

 Inaugural-Dissertation zur Erlangung 

 der Doktorwiirde . . . der Kgl. bayer. 

 Ludwig- Maximilians -Universitiit zu Miinchen, 

 p. 23. 



Description. — Shell moderately elongate, straight, tapei'ing rapidly. Section 

 elliptic, this form being due partly to pressure, as it is present in a lesser degree 

 in one of the specimens. The diameters of the ellipse are in the ratio of 

 about 4:3. Rate of tapering of the greater diameter estimated for the septate 

 part of the shell 1 : 5. Body-chamber not complete in any specimen ; an 

 impei'fect one measures 65 mm. in length, is 28 mm. in diameter at its base, and 

 46 mm, at the anterior end. Septa very concave, oblique to the longitudinal axis 

 of the shell, distant 7 mm. where the larger diameter of the shell measures 27 mm. 

 The siphuncle is large and considerably expanded between the septa, thus pre- 

 senting a characteristic moniliform appearance. It is markedly excentric in 

 position. Test quite smooth. 



Size. — The largest specimen, which is all septate (the extreme apex wanting), 

 measures 200 mm. in length. The other specimens are moi'e or less fragmentary. 



Affinities. — The differences which serve to distinguish this species from its 

 congeners, Orthoceras suhclavatum and 0. pilum, are not difficult to recognise ; the 

 large size of its beaded siphuncle, and its high rate of tapering are sufficient guides, 

 though it must be remembered that the former is not generally to be seen without 

 the aid of the lapidary's wheel. 



EemarJiS. — I have named this species after Dr. G. J. Hiude, F.R.S. 



Locality. — Little Island, near Cork. 



