NO. 1704. A (COLLECTION OF f^TTELLS FROM PEkU—DALL. lYl 



or angiilate keels; the whole shell spirally threaded, with an axially 

 lamellose band appressed at the suture; shell white with an oliva- 

 ceous periostracum, the threads sometimes brownish, and the interior 

 of the aperture sometimes spirally brown threaded; pillar without 

 plaits, the operculum with a lateral nucleus. Ijength about 36 mm. 



Specimens preparetl for market by breaking ofl' the greater part 

 of the last whorl were also sent in by Mr. Coker. This species has 

 been widely confused with Cymia (or Ouma) and Solenosteira. From 

 the first it may be known by the absence of the strong plait or keel 

 in the middle of the pillar, and from the second by its laterally 

 nucleated operculum and the lamellose sutural band. 



Several other species of Thais have been used since prehistoric 

 times by the natives of Central America as a source of purple dye. 

 The most commonly used species there is TJiais iPatellipurpura) 

 'patula Linnseus. Many years ago the writer, at San Juan del Sur, 

 Nicaragua, stained a handkerchief with the unmixed purple from 

 one of these shells. Perhaps because lemon juice or other mordant 

 was lacking the color faded considerably during three years that the 

 handkerchief was kept, and the color was not at any time brilliant, 

 resembling the water color known as "neutral tint." Senora Zelia 

 Nuttall, of Mexico City, well known for her profound ethnological 

 researches, has recently read a paper before the American Association 

 for the Advancement of Science on the prehistoric use of these 

 Molluscan purples in Mexico and Central America. 



BURSA VENTRICOSA Broderip. 



Ranella ventricjsa Broderip, Proc. Zool. Soc. of London for 1832, p. 178. — 



SowERBY, Conch. III., Ranella, 1839, pi. 92, fig. 116. 

 Ranella tenuis Potiez and I^Iichaud, Galerie de Douai, Moll., vol. 1, 1837, 

 p. 426, pi. 34, figs. 1, 2. 

 Dredged in Callao Bay, in about 2^ fathoms, near the northeast side of San Lorenzo 

 Island. Also sold in Callao market, among other gastropods, under the name of 

 Caracoles. 



Distribution. — Nicaraguan coast and south to Callao, Peru. 



Shell thin, whitish, obscurely rugosely sculptured or smooth, with 

 lateral varices, a large aperture, with thickened and varicose outer 

 lip, with a wide and deep canal near the junction of the lip and the 

 body whorl. 



CYMATIUM VESTITUM Hinds. 



Triton vestitus Hinds, Zool. Sulphur's Voy., Moll., p. 11, pi. 4, fig. 1, 1844. 

 Chincha Islands, among the rocks. 



Distribution. — West coast of Central America and southward to 

 the Chincha Islands, Peru. 



Shell rather large, thin, with a moderately elevated spire and 

 strong spiral ribs; surface covered with a dense lamellose periostracum 



