PLATE XX. 



CffiLONAUTILtJS GBADUS, A. H. FoOvd. 



Eig. 1 a. Lateral iispect of an adult and nearly perfect individual, showing the faint folds on the 

 sides of the inner whorls. 1 h. Part of the periphery of another specimen, showing the longitudinal 

 ridges. Kildare. British Museum. (Page 57.) 



rig. 2. Polished section of another individual, showing the septa and siphuncle, and almost the 

 whole of the body-chamber. Kildare. British Museum. (Page 57.) 



Fig. 3. Peripheral view of an individual in which strong nodular folds are developed as well as 

 ridges ; the edge of the aperture is seen. Curraghbridge. Dublin Museum of Science and Art 

 (Geological Survey Collection). (P^'ge 57.) 



Pig. 4. View of the inner whorls of another individual, showing their quadrate form and the 

 position of the siphuncle. Rathkeale. Dublin Museum of Science and Art (G-eological Survey 

 Collection). (Page 57.) 



The following are considered to be the young of this species ; they are all from Eathkeale and are 

 contained in the Dublin Museum of Science and Art. 



Fig. 5. Lateral aspect of a specimen, showing the slight folds on the inner whorls (cf. Fig. la). 

 (Page 57.) 



Fig. (J. Peripheral view of a specimen, showing the outline of the aperture, and some of the fine 

 and sharp longitudinal ridges. (Page 57.) 



Fig. 7 a. Lateral view of a specimen, showing the sutures of the septa. 7 b. Front view of the 

 same individual. (Page 57.) 



Fig. 8 a. Lateral aspect of a specimen, showing the minute crenulations on the peripheral and 

 umbilical edges (the drawing necessarily makes them appear coarser than they are in nature). 8 5. 

 Part of the peripheral area of the same individual, showing the fine longitudinal ridges, and the 

 sinuous lines which indicate the position of former .npertures of the shell. (Page 57.) 



Fig. 9 a. Part of the outer and inner whorls of a specimen, showing their quadrate form and the 

 position of the siphuncle. 9 5. Part of the inner whorls of the same individual, the smaller showing, 

 with the aid of a lens, fine longitudinal lines (indicated in the figure), as well as minute transverse 

 lines too fine to be represented. (Page 57.) 



Stroboceeas sulcatum, J. de G. Sowerby, sp. 



Fig. 10 a. Lateral aspect of a specimen, showing the ornamentation. 10 5. Peripheral view of the 

 same. Little Island, near Cork. Dublin Museum of Science and Art. (Page 60.) 



Fig. 11. Lateral view of a distorted but well-preserved individual, showing the apical point and 

 ornamentation. Little Island, near Cork. Dublin Museum of Science and Art. (Page 60.) 



Fig. 12. Lateral aspect of a very iun^erfect specimen, showing,' the septa. Mullaghfarry, Killala. 

 Dublin Museum of Science and Art (" txriffith Collection "). (Page 60.) 



Steoboceeas ceassum, sp. nov. 



Fig. 13 a. Lateral view of a fragment of the body-chamber, showing the ridges and sulci. 13 h. 

 View of the periphery of the same, showing the superiority of its breadth to that of Strohocerns 

 sulcatum. 13 c. Transverse section of the same in outline, lling, near Enniskillen. Dublin Museum 

 of Science and Art (" GriflBth Collection "). (Page 64.) 



Mesochasmocekas latidoesatum, F. IFCoy, sp. 



Fig. 14 «. Lateral view of a nearly perfect specimen. 14 5. Portion of the same, showing the 

 sutures of the septa. Argoul South. Dublin Museum of Science and Art (Geological Survey 

 Collection). (Page 73.) 



Fig. 15 «. Another specimen, imperfect at both extremities. 15 5. View of the periphery of the 

 same, showing the fine ridges near its margins. 15 c. Body-chamber (fragment) of the same, detached 

 from the septate part of the shell, showing the zoiie of impression and the form of the whorls as seen 

 in transverse section. 15 d. Another piece of the same specimen, showing part of the innermost 

 whorl and the position of the siphuncle. Cragard. Dublin Museum of Science and Art (Geo- 

 logical Survey Collection). (Page 73.) 



