PLATE X. 



Fig. 



1. Eschar a Sedgwichii, p. 67. 



2. „ pertusa, p. 65. 



3. ,, incisa, p. 65. 



4. Melicerita Ckarlesworthii, p. 70. 



a. Portion magnified 50 diameters. 



b. Portion magnified 25 diameters. 



c. c. Fragments, natural size. 



d. Old or worn condition, magnified 25 diameters. 



e. Section. 



5. Eschara cornuta, p. 67, natural size. 



6. ,, sinuosa, p. 66. 



a. Portion of surface, magnified 25 diameters. 



b. Older state, maguified 25 diameters. 



c. c. Natural size. 



d. Section, magnified 25 diameters. 



7. Hemeschara imbellis, p. 78 (natural size). 



