332 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.56. 



which is semilimate ; outer lip hardly thickened, whitish. Urate 

 within; ]>ody and pillar with a layer of whitish enamel; canal short, 

 <leep. shghtly recurved; height of shell, 13.5; of last whorl, 10; of 

 aperture, 6.5; diameter, 7 mm. U. S. Nat. Mus. Cat. No. 12285. 



Type-locality. — Laguna Beach, California; Stearns collection. Dif- 

 fers from the typical versicolor by the strength of the sculpture, deep 

 grooving, and generally by the duller color. 



AESOPUS ARESTUS, new species. 



Shell small, thin, slender, suffused with j-ellowish and white or 

 ocellated somewhat Uke NitideUa ocellata with pale brown on a 

 white ground, with six subcyUndric whorls including a smooth 

 swollen nucleus of about one whorl; suture distinct, not approssed; 

 axial sculpture of numerous narrow nearly obsolete vertical riblets 

 on the upper part of the spire, Avhich are absent from the last whorl, 

 except in the form of feeble vertical wrinkles; spiral sculpture none; 

 aperture short, simple, outer Up thickened, not reflected, body with 

 a layer of enamel, pillar lip thickened, slightly twisted, shorter than 

 the outer lip; canal very short and deep; height of shell, 7; of last 

 whorl, 3.8; diameter, 2 mm. U. S. Nat. Mus. Cat. No. 217928. 



Type-locality. — Magdalena Bay, Lower California; coUecte<l by 

 C. R. Orcutt. 



MUREX (ALCPLRPURA) RHYSSUS, new species. 



SheU elongate, trialate, white, with a rasplike surface, a dark brown 

 nucleus of two whorls, and five subsequent whorls, Avitli a narrow 

 shoiilder in front of an obscure appressed suture; axial sculpture be- 

 side the tliree varices and the minute imbricate surface includes a 

 nodulous rib between each pair of varices; the latter are slightly 

 recurved with a prominent spinosity at the shoulder, about six 

 major the same number of minor, and numerous smaller imbricate 

 intercalary riblets in the last varix, which extends nearly to the end 

 of the long closed canal; aperture ovate, white, simple, entire; oper- 

 culum normal, brown; height of shell, 62; of last whorl, 47; of aper- 

 ture, 12; maximum diameter, including the varix, 27 mm. U. S. 

 Nat. Mus. Cat. No. 160500. 



Type-locality. —Sm\ Pedro, California; collected by Mrs. Oldroyd. 



PURPURA NUTTALLII Conrad, 1838. 



There are two color varieties which seem worthy of distinction, 

 one completely white or yellowish white, which may take the name 

 of P. nuttallii albescens, and another, which, generally preserving 

 the usual brownish color, has a broad white band, making it very 

 conspicuous, about the middle of the sheU, and one on the canal, 

 which may be caUed P. nuttallii alhofasciata. These color-varieties 

 appear to be unusually constant and are found chiefly in the southern 



