ACM^EA. 35 



Lottia variabilis SOWERBY (in part), Zool. Beechey's Voy. p. 147, 

 t. 39, f. 5, not figs. 3, 4; 1839. Patella variabilis Gray, RVE., Conch. 

 Icon. t. 25, f. 63, 1855. P. penicillata RVE., /. c., f. 102. P. 

 (Acmcua*) lineata Phil., Abbild. iii, t. 2, f. 1 (1846). 



This is unquestionably a distinct species, characterized by its 

 depressed contour and mottled central area. The outside is usually 

 much eroded. The black lines of the exterior are often interrupted, 

 and in large specimens they are arranged in about a dozen broad 

 but indistinct bands. The synonymy given above is unquestionable. 



A. ARAUCANA Orbigny. PL 16, figs. 21, 22, 22. 



Shell ovate, extremely depressed, costate, whitish, inside whitish, 

 margin crenulated, brownish. Diam. 30, alt. 4 mill. ( Orb.') 



Valparaiso. 



P. araucana ORB., Voy. Amer. Merid., p. 482, t. 65, f. 4-6. 

 Collisella araucana DALL, Amer. Journ. Conch, vi, p. 257 (animal). 

 f Patella plana PHIL., Abbild., Patella, t. 2, f. 3. P. plana Rv., 

 Conch. Icon., f. 133. 



The specimens before me are longer than Orbigny's figured type, 

 and the ribs are more separated. The shell is frequently distorted. 



I am inclined to believe that A. plana of Philippi is a synonym or 

 variety of A. viridula; but A. plana of Reeve is very probably a 

 synonym of araucana. My material is too limited to enable me to 

 decide this question. 



A. COFFEA Reeve. PI. 4, figs. 91, 88. 



Shell ovate, convexly depressed, radiately densely ridge-striated, 

 always very much eroded ; brown-black within and without, finely 

 denticulated at the margin, (/fry.) 



Valparaiso. 



P. co/ea Rv., Conch. Icon., f. 139, 1855. 

 A. EXILIS Philippi. PI. 4, figs. 89, 90, 91. 



Shell minute, thin, elongate-elliptical, convex, smooth, white, 

 painted with brown rays ; apex at the front third. 



Length , breadth 4, alt 2^ mill. 



In size and form just like Patelloidea elongata Q. & G., and per- 

 haps is only a variety of it. That species should be netted over a 

 greenish-yellow ground, according to the description ; but the illus- 

 tration of it shows simple red rays upon a gray ground, the two pos- 

 terior rays broader and darker ! The present species has about 20 



