Murdoch. — Additions to Marine Mollusca of N.Z. 223 



Leptothyra crassicostata, n. sp. Fig. 11. 



Shell small, solid, turbinate, with strong variable spiral 

 sculpture. Colour whitish or light brown, occasionally with 

 irregular markings of brown, most distinct on and below the 

 periphery. Whorls 4, spire short, apex minute and without 

 sculpture. The penultimate whorl with three to five, and the 

 last with twelve to twenty, spiral ribs, four to nine of which are 

 in front of the aperture. The ribs are very variable in size ; 

 there are five to eight strong riblets between the periphery and 

 suture on the outer lip ; in front of the aperture four or five 

 about equal to the breadth of the interspaces. On and im- 

 mediately below the periphery frequently small and crowded, 

 similar on the base, or there may be two or three more prominent 

 intercalated with the smaller spirals, or the basal riblets generally 

 stronger than those on the periphery. The growth-lines strong 

 and irregular, producing here and there a lightly costate appear- 

 ance, frequently pronounced in the umbilical area. Sutures 

 impressed. Aperture subrotund. Outer lip sharp, descending, 

 rather sharply in some. Columella lightly curved, somewhat 

 produced and expanded anteriorly, a thick posterior callus 

 spreading across to the outer lip. Umbilicus small and deep. 

 Operculum circular, somewhat calcareous, of six or seven narrow 

 folds, the nucleus central. Height, 2- 49 mm. ; breadth, 3-21 mm. 



Type in the Colonial Museum. 



Hab. Whangaroa Harbour (Mr. A. Hamilton). 



Distinguished from L. fluctuata, Hutton, by its much stronger 

 sculpture. 



Columbella huttoni, Suter, nom. mut. Fig. 12. 



Lachesis sulcata, Hutton, Cat. Marine Moll. N.Z., p. 12 (1873) : 



Cat. Tertiary Moll, and Echin. N.Z., p. 5 ; Manual N.Z. 



Moll., p. 45. Columbella huttoni, Suter, for sulcata, Hutton. 



preoccupied, "Index Faunae Novae-Zealandiae," p. 72 (1904). 



The specimen figured is from the material collected by Mr. A. 

 Hamilton at Whangaroa Harbour. The shell is small, robust, 

 with well-marked spiral riblets somewhat wider than t\\e grooves ; 

 last whorl longer than the spire, lightly carinate, more distinct in 

 front of the aperture. Colour ash-grey, brown, or reddish-brown, 

 sometimes variegated with white. Whorls rather flattened, 6 in 

 number, including a 2- or 2|-whorled smooth reddish-brown 

 protoconch. Sculpture : On the penultimate whorl five and 

 on the last twelve to fourteen spiral riblets, five of which are in 

 front of the aperture ; a few of the riblets on the anterior end 

 are minute, sometimes absent. These are crossed by irregular 

 growth-lines, which give to the shell a slightly roughish appear- 

 ance. Sutures impressed. Aperture oval, outer lip simple ; 



