PLATE XLVIII. 



Fig. 1. — Allorisma variabilis. A specimen from the Calderwood Limestone, 

 Kirktonholm, East Kilbride, showing the pallial sinus. In the Collection of Mr. J. 

 Neilson. (Page 424.) 



Fig. 2. — Allorisma variabilis. Another example. Same locality and Collection. 

 (Page 424.) 



Figs. 3, 4. — Allorisma sulcata. Two specimens from the Redesdale Ironstone 

 beds, showing sinuated pallial line. My Collection. (Page 422.) 



Figs. 5, G. — Allorisma sulcata. Two specimens from the same locality, of 

 medium size. Fig. 5 someAvhat incomplete posteriorly, and therefore appearing to 

 gape posteriorly. Fig. 6 shows that the shell was closed all round. My Collection. 

 (Page 422.) 



Fig. 7. — Allorisma sulcata. A specimen having the outer test preserved, 

 and showing the radiating rows of small tubercles, of which 7 a is a magnified 

 view, and 7 6a view of the umbones, escutcheon, and lunule. From the Upper 

 Limestone Series of Garngad Road, GlasgoAv. In the Collection of Mr. J. Neilson. 

 (Page 422.) 



Fig. 8, — Allorisma sulcata. A large example from the Lower Limestone 

 Series of Beith, showing sinuated pallial line. My Collection. (Page 422.) 



Fig. 9. — Allorisma sulcata. A young example from the Redesdale Ironstone. 

 My Collection. (Page 422.) 



Figs. 10, II. — Allorisma sulcata. Two uncrushed examples with strongly 

 marked ribs. Figs. 10 a, 11 a, showing the lunule and escutcheon. Same locality. 

 My Collection. (Page 422.) 



Fig. 12. — Allorisma monensis. The cast of a full-grown example, showing 

 adductor muscle-scars and sinuated pallial line. From the Lower Limestones of 

 Balasala, Isle of Man. With Fig. 12 «, a view from above, showing cast of 

 lunule and escutcheon. My Collection. (Page 426.) 



Fig. 13. — Allorisma monensis. An incomplete specimen, but possessing 

 fragments of the test, showing the character of the external marking, anterior and 

 posterior adductor muscle-scars, and sinuated pallial line. Same locality. In the 

 Collection of Miss Birley. (Page 426.) 



Fig. 14. — Allorisma monensis. The same specimen, showing the right valve, 

 with a portion of the test preserved. (Page 426.) 



