PLATE VI. 



Orthoceras hibernicum, A. H. Foord. 



Fig. 1 a. Specimen almost entirely covered with the test. 1 b. Longitudinal 

 section of the same, showing in the lower part the somewhat inflated siphuncle. 

 1 c. Septum showing the siphuncle. 1 d. The same nearer the apical end. 

 1 e. The ornamentation enlarged. Clane. Dublin Museum of Science and Art. 

 (Page 19.) 



Orthoceras pulcherrimum, A. H. Foord. 



Fig. 2 a. Fragment consisting of nearly the whole of the body-chamber and 

 some of the septa. 2 b. Longitudinal section of the same. 2 c. Portion of the 

 test greatly magnified. Clane. Dublin Museum of Science and Art. (Page 19.) 



Orthoceras Kildarense, A. H. Foord. 



Fig. 3 a. Fragment composed of the body-chamber and five septal chambers. 

 3 b. Section of the same showing the siphuncle. 3 c. Fragment of another 

 individual, with part of the test preserved. 3 d. Part of the test enlarged. 

 Clane. Dubliu Museum of Science and Art. (Page 17.) 



Orthoceras salvum, L. G. de Koninck. 



Fig. 4 a. Specimen completely covered with the test. 4 b. The test magnified. 

 Doohyle. Dublin Museum of Science and Art. (Page 18.) 



