99 



the last whorl the slender costee stop short at the periphery. 

 Pull us of smooth whorls. 



This species is closely related to R. trajectus, Watson, but 

 differs by more elongate shape, arched ribs, and rounded whorls* 

 also to It. Strangei, Braz., which has closer and stronger ribs, fewer 

 -spiral striae, and the shell short and stout. 



Tasmania. 



Rissoia (Apiculapia) apieilirata, spec. nov. 



Elongate-conic, thin, yellow-fawn, smooth, shining. Pullus 

 hyaline, turbinate, two-whorled, ornamented with three, spiral, 

 simple, relatively broad and high keels. Whorls three, slightly 

 bicarinated, the posterior slope somewhat concave, the anterior 

 slope steeper and shorter; ornamented by transverse slender 

 ridges (about twenty on the penultimate), which are oblique 

 on the posterior slope, vertical thence to the front suture; 

 there is a spiral thread at the posterior suture, and a threadlet 

 near the anterior rows ; two spiral rows of small nodosities 

 occupy the near middle-third of the whorl. 



Periphery of last whorl with four riblets crossed by costulse, 

 and there are a few others on the base which gradually decrease 

 in size. 



Aperture oval ; peristome entire, thin. 



Length, 2*2 ; width, 9 mm. 



D'Entrecasteaux Channel, Tasmania. 



This species is unique in the section by reason of its ornate 

 .pullus. 



Rissoia (Pusillina) discrepans, spec. nov. 



Shell oval-conic, thin, greyish, pale rose-tinted at the apex. 



Pullus somewhat hemispheric of two smooth whorls. Spire- 

 whorls four, nearly flat, suture impressed ; ornamented by 

 numerous slender subacute axial ridges, interstices smooth. Last 

 whorl subangulated, the axial costation evanescent towards the 

 anterior part ; an indistinct lineation is at the periphery, as also 

 one above and one below, all in near contiguity; base finely 

 striated radially. 



Aperture oval, outer and inner lips thinly callously joined ; 

 outer lip thin (slightly varicosely dilated behind, front lip with a 

 slight insinuosity — these features are probably the result of an 

 injury during life). Columella slightly exsert, margining a linear 

 umbilical chink. 



Length, 3; width, 1;6 mm. 



D'Entrecasteaux Channel, Tasmania. 



The ornament and shape, in combination with the angulated 

 base, distinguish this species from all figured species. 



