36 ACM^EA. 



to 24 dark reddish-brown rays, mostly in pairs, the interstices often 

 milk-white, and a brown apex. The inside is similarly colored. 

 One specimen is flatter. (Phil.) 



Cape Horn. 



A. exilis PH., Zeitschr. f. Mai. 1846, p. 50 ; Abbild. iii, t. 2, f. 6. 

 Probably a young shell. 



A. ALBESCENS Philippi. PI. 4, figs. 85, 86, 87. 



Shell small, thin, ovate-oblong, elliptical, conical, sculptured 

 with close, little elevated, obsolete radiating ribs ; whitish, sometimes 

 radiated and spotted with brown ; apex elevated, situated at the 

 front third. Inside white, margins incumbent at the ends. 



Length 10, width 7J, alt. 4 mill. 



Six specimens are before me. In the young the acute apex is very 

 prominent, and also the ribs, of which I count about 24, are much 

 more distinct. With age they become more and more obsolete, 

 and in old examples which have lost the apex by erosion, they 

 often can not be recognized with certainty. Young examples are 

 frequently pure white with yellowish apex ; older ones have more or 

 less brown markings. The border is pale brownish, and does not lie 

 in a plane, for the sides are higher than the ends. The inside is 

 white, or brownish when there is brown to be seen outside. (Phil.') 



Central Chili. 



A. albescens PH., Zeitschr. f. Mai. 1846, p. 50; Abbild. iii, t. 2, 

 f. 7. 



This seems to be young. 



*** 



IV. WEST INDIAN SPECIES. 



Many specimens of all described West Indian Acmaeida3, except 

 the doubtful A. Antillarum Sow., have been examined by the 

 author. 



The West Indian Acmseas are few in number and of small size. 

 Their affinities are with the species of western Mexico. The syn- 

 onymy is involved in great confusion. Of the four commoner species 

 I have seen hundreds of specimens, and am still inclined to consider 

 them quite distinct. 



The Acmcea hamillei of Fischer (Journ. de Conchyl. v. p. 277, 

 and J. de C. 1872, p. 145, PI. 5, f. 6) is the same as Seutellina antil- 

 larum (Shutt.) Dall, and as the latter was until 1890 a mere mss. 

 name, the species should hereafter be known as Seutellina 

 hamilltti. 



