180 



SYSTEMATIC ARRANGEMENT 



A. Mantles without any pores, furnished with fascicles of bristles 

 or spines on the sides. 



a. The exposed part of the valves broad, band-like, transverse, 

 closely imbricate one on the other. The plates of insertion 

 moderate, of the anterior and the posterior valve divided into 

 several lobes more or less pectinated on the edge. 



* Margin covered with uniform scales, entire behind. 



1. Chiton. 

 Margin covered with regularly disposed, imbricate, smooth, polished 

 scales ; valves thick ; the plates 



of insertion pectinately lobed, of Fig. 96. — Valves of Chiton olivacem. 

 the central valve with a single sub- 

 central notch, of the hinder valve 

 broad, distinctly lobed and pecti- 

 nated ; the hinder valve entire ; 

 apex superior, subcentral (fig. 96). 

 The gill occupying nearly thewhole 

 length of the sides of the foot. 



f Scales of the margin moderate- 



tfe. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18, 



19. 

 20. 

 21. 



Ch. striatus, Sow. III. f. 3, 4 1 . 



Chiloe. 

 Ch. Cumingii, Sow. III. f. 32, 



51. Chili. 

 Ch. albolineatus, Sow. III. 



f. 39. Mexico. 

 Ch. squamosus. West Indies. 

 Ch. sulcatus, Sow. III. f. 1 2. 

 Ch. granosus. Chili. 

 Ch. glaucus. 



Ch. granulosus. Conception. 

 Ch. Siculus. 



Ch. liratus, Sow. III. f. 126. 

 Ch. foveolatus, Sow. III. f. 60. 

 Ch.excavatus, Sow. III. f. 131 . 

 Ch. fasciatus, Sow. III. f. 153. 

 Ch. australis, Sow. III. f. 46. 

 Ch. Stokesii, Sow. III. f. 24. 

 Ch.virgulatus, Sow.Ill.i. 132. 

 Ch. patulus, Sow. III. f. 134. 

 Ch. marmoratus, Sow. III. 



f. 148. 

 Ch. articulatus, Sow. III. f. 18. 

 Ch. laevigatas, Sow.IlU. 18*. 

 Ch. Goodallii, Sow. III. f. 50. 





anterior, B, middle, and C, terminal 

 valves. D, E, F, inner surface of 

 same valves, g, the small lobes in 

 the middle of the anterior margin 

 between the wings. A,«,&£,notches 

 in margin of insertion, l&m, con- 

 fines of central area. 



