PLATE X. 



ACTINOCERAS INSULARE, Sp. nOV. 



Figs. 1 a, 1 b. Fragment of a portion of the septate part of a large specimen, 

 showing the very oblique septation ; a considerable part of the smooth test is 

 present, so that the septa are not seen on the lower half of the specimen. 1 c. 

 Transverse section showing the position of the siphuncle. 1 d. Longitudinal 

 section showing siphuncle and endosiphuncle, with obscure remains of the tubuli 

 attached to the latter. Little Island. Dublin Museum of Science and Art. 

 (Page 30.) 



