BY K. M. JOHNSTON, F.L.S. 



121 



or hollow (12 a .) It is sub-umbilicated, 

 or sub-perforate when partly covered 

 over by shelly matter (L6), It is 

 not umbilicated or non-perforate, 

 where the axis of the shell is solid. 



Example fig 

 No. 



SOULPTUEE OK COLOITE MARKINGS. 



These are : — 



1. Longitudinal, when taking the 



direction of the axis. 



2. Bevolving or transverse, when they 

 follow the spiral. 



3. Canaliculate. Suture deeply chan- 

 neled 



4. Cingulate. Encircled by revolving 

 ribs 



5. Carinate, revolving sculpture pro- 

 minent, sharp 



6. Sulcate, encircled by channels . . . 



7. Plicate, costate, ribbed. Sculpture 



longitudinal ... 



8. Nodosely, tuberculately, granosely 



plicate, when the ribs are broken 

 up into tubercles or granules ; 

 mostly caused by the intersection 

 of revolving sculpture ... 



9. Striate, covered by fine close lines, 

 either longitudinal or revolving. 



10. Punctate, pitted. Frequently punc- 

 tate, striate, i.e., 9 & 10 combined 



11. Granulate, nodose, tuberculate, 

 covered with nodules of small or 

 large size, but not ribbed 



12. Muricate, spinous, echinate when 



the nodules are sharp pointed. 



13. Decussate, cancellate, longitudinal 

 and revolving sculpture, crossing 

 at right angles. 



14. Eeticulate, sculpture not crossing 



at right angles, irregularly de- 

 cussate. 



15. Clathrate, longitudinal and re- 

 volving lines both distant, forming 

 a pattern somewhat like the iron 

 bars of a prison window. 



10. 



9 

 11 



4, 5,8 



11 



