PLATE XXVI. 



Thrincoceras Hyatti, sp. nov. 



Fig. 1 a. Peripheral view of a specimen. 1 h. Lateral view of the same, 

 showing the fine ridges covering the whole of the shell. 1 c. Part of another 

 specimen, showing the impressed zone, also ridged. 1 d. Ornamentation (from 

 1 h, the side of the shell) enlarged about twelve times. 1 e. The same slightly 

 enlarged. If. The same in the very young shell. 1 g. Septum of another 

 specimen, showing position of siphuncle. St. Doulagh's. Museum of the Royal 

 College of Science for Ireland, Dublin, except 1 g. (Page 98.) 



Thrincoceras hibbrnicum, A. H. Foord, sp. 



Fig. 2 a. Lateral aspect of an imperfect specimen, showing the septa of the 

 inner whorls. 2 b. Peripheral view of the same, showing the lines of growth 

 crossing it in a sinuous manner. Glenbane. Dublin Museum of Science and Art 

 (Geological Survey Collection). (Page 101.) 



DiSCITOCERAS WuiGHTII, Sp. nOV. 



Fig. 3 a. Lateral view of an imperfect but uudistorted specimen, showing the 

 ornamentation. Midleton. Dublin Museum of Science and Art. 3 /). Lateral 

 view of a distorted specimen, showing some of the coarser lines of growth. 3 c. 

 Section, transversely to the whorls, of another specimen, showing the position 

 of tlie siphuncle. 3 d. Bead-like ornamentation taken from 3 a. Little Island. 

 Dublin Museum of Science and Art. (Page 105.) 



