2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



immediately above the basal angle, and the last is on the anterior half 

 of the base. The outside of the columella is of the same color as the 

 base ; its inside, as well as the inside of the aperture, is yellowish, the 

 outer lip showing the darker bands, described for the exterior, within. 

 Nuclear whorls decollated. The postnuclear whorls are encircled by a 

 deeply impressed groove at about two-fifths of the distance between 

 their summit and the periphery anterior to the summit. They are 

 crossed by low broad axial ribs, which in turn, as well as the inter- 

 costal spaces, are marked by fine incremental lines. Of these ribs 33 

 are present on the last whorl. The spiral sculpture is reduced to 

 microscopic striations. The suture appears as deeply impressed as the 

 groove anterior to it. Periphery well rounded. Base short, well 

 rounded, marked by the continuations of the axial ribs and fine incre- 

 mental lines, which extend to the columella. Columella short, thick, 

 with a strong oblique fold which is separated from the base by a 

 decided groove. Anteriorly to the fold the columella is somewhat 

 twisted and marked by strong incremental lines. On the inside the 

 columella shows a second low rounded fold bordering its anterior 

 termination. Aperture auriculate, decidedly channeled anteriorly, the 

 outer lip thin, somewhat contracted above the groove posteriorly. 



The type, U.S.N.M. no. 472534, has 12.5 whorls remaining and 

 measures: Length, 43.2 mm.; greater diameter, 14. 1 mm.; lesser 

 diameter, 14.0 mm. It was dredged on Socorro Island, Mexico, in 

 7-8 fathoms on sandy bottom, off the landing beach toward the rocky 

 point forming the east side of the cove. 



APLYSIA CEDROSENSIS, n. sp. 



Plate 4, figs. 8-10; plate 5 



Animal large, stout, rather broad and high. The color (in alcohol) 

 is arranged as follows : The head, the foot, the sides of the body, and 

 the exterior of the pleuropodia (or lateral lobes) are black; the 

 dorsal area is gray from the rhinophores to the posterior edge of the 

 mantle, except for a black area extending posteriorly from between 

 the rhinophores for an inch and a half and becoming narrower, and 

 a narrow irregular black patch extending along the middorsal line 

 anterior to and over the mantle ; the interior of the pleuropodia are 

 irregularly maculated with black, as is the area about the mouth and 

 buccal appendages. The skin is strongly wrinkled, especially the sole 

 of the foot, the head regions, and the exterior of the pleuropodia. The 

 head bears rather broad, folded buccal appendages. The rhinophores 

 or tentacles are elongately conic and noticeably slit. The foot is broad 



