144 . FISSURELLA. 



Group of F. picta Gmel. 



F. PICTA Gmelin. PI. 45, figs. 9, 10, 11. 



Shell conical, elevated, basal outline elliptical, the summit about 

 central ; having radiating riblets and strong concentric undulations ; 

 perforation oblong, twice as long as wide, about one-ninth the 

 length of shell. Length of shell a trifle less than 1 \ times the width. 



The outline is elliptical, a trifle narrower in front. The slope ot 

 the sides is nearly straight, somewhat shorter and steeper in front. 

 Color whitish with broad radiating stripes of purplish-red, about a 

 dozen in number. The radiating riblets are numerous and some- 

 what unequal, not granose ; they pass over from four to seven strong 

 concentric folds, which give the slope a terraced appearance, when 

 strongly developed. Inside white, smooth, with a narrow, grayish 

 or purple-black edge. Muscle impression not rough, the area be- 

 tween its terminations and the perforation scarcely wrinkled. Mar- 

 gin entire. Sides of hole vertical. Length 82, width 56, alt. 28 mill. 



Valparaiso, Chili. 



Patella picta GMEL. in Syst. Nat. xiii, p. 3729. Fissurella picta 

 GOULD, U. S. Expl. Exped., atlas, t. 31. fig. 469, animal. Un Lepas 

 rare de Magellan, etc., DAVILA, Cat. Syst. et Raisonne des Cur. etc., 

 i, p. 88, t. iii, f. C. 1767. Lepas ovata ampla, etc., MARTINI Syst. 

 Conchyl. Cab. vol. i, p. 131, t. xi, f. 90. 



I have omitted all references except those of Gmelin, whose know- 

 ledge of the species was derived from Davila and Martini. 

 Martini, too, seems to have known the shell from Davila's work 

 only, and copied his figure. The illustration and especially the de- 

 scription given by Davila are excellent and unmistakable. I 

 suppose that this is the F. picta of Reeve and other authors, but 

 none of them give any differential characters from F. maxima either 

 in figures or descriptions. The great altitude and strong concentric 

 ridges are diagnostic. The dark rays are split into groups of lines 

 by the white inter-liral interstices more than in F. maxima. The 

 riblets are more equal than in F. lata, and the form is longer. 



F. DARWINII Reeve. PI. 30, fig. 7 ; pi. 46, figs. 15, 16, 17. 



Shell oblong, conical, the summit a little in front of the middle ; 

 sculptured with numerous low rather obscure radiating riblets 

 which are a little uneven but scarcely to be called granose. Per- 



