FISSURELLA. 153 



P. mexicana Sowerby. PI. 34, fig. 60. 



Shell oblong, reddish-brown with darker rays and numerous close- 

 set radiating grooves, which are decussated by very fine concentric 

 stria? ; dorsal aperture oblong, rather contracted in the middle, and 

 with two obsolete teeth on each side ; inside white with a purple- 

 brown crenulated margin. (Soiv.) 



Length 1"25, breadth 056 inches. 



Real Llejos, Mexico. 



F. Mexicana Sow. Conch. 111. Fissurella p. 8, fig. 61. — Reeve, 

 Conch. Icon. f. 40.— Sowerby, Thes. Conch, iii, p. 186, f. 26, 27, 



28, 78. 



The orifice, says Reeve, has a very decided white border. I have 

 not seen authentic examples. Compare F. oriens Sowb. The local- 

 ity needs confirmation ; for, as I have shown on page 143 , the spe- 

 cies of this group do not extend above Peru. 



F. latemarginata Sowerby. PI. 32, figs. 36, 37, 38. 



Shell depressed, ovate, narrower anteriorly, summit a trifle in 

 front of the middle ; radiately finely striated all over. Perforation 

 oblong, twice as long as wide, with straight, parallel sides, its length 

 contained 8£ times in the total length of the shell. 



The shell is depressed, egg-shaped in outline, the front part being 

 narrower ; it is solid, of a uniform reddish purple color outside, 

 white with a broad dark purple or chocolate border inside. The in- 

 terior has indistinct radiating fine strise. The muscle-impression is 

 quite broad, and is near to the wide dark margin. The sides are a 

 little arched, so that when resting on a flat surface the ends alone 

 support the shell. 



Length 68, breadth 50, alt. 12 mill. 



Length 69, breadth 49, alt. 11 mill. 



Chili ; Peru. 



F. latemarginata Sow. P. Z. S. 1834, p. 126 ; Conchol. Illust,, f. 

 69. — Reeve, Conchol. Icon., f. 19. — Sowerby, Thes. Conch, iii, p. 

 185, f. 6, 7, 12. 



The broad purple border of the interior, and fine striation and 

 uniform color of the outside are characteristic. 



