428 



over the basal part of whorls is crossed by faint spirals, 2 in number on penultimate, about 10 in 

 slightly contracted last whorl, of which latter the upper ones are more conspicuous, bead-like 

 in crossing the ribs, those on the canal plain, lastly the whorls are crossed by growth-lines. 

 Aperture elongately oval, angular above, with a short, wide canal below; peristome thin, broken, 

 according to growth-lines with a wide, rather deep sinus above, then considerably protracted, 

 columellar side concave above, slightly tortuous below, with a conspicuous, appressed layer 

 of enamel. 



Alt. Sy^, lat. 37^; apert. alt. 37,, lat. 17^ Mill. 



Though small, I think this form to be distinct and not to be identified with the young 

 of any described species. 



14. Stu'cnia sp. 



Stat. 178. 2°40'S., 128° 37'. 5 E. Ceram-sea. 835 M. Blue mud. 2 Spec. 



These specimens are nearly allied to the preceding species, they are a little narrower 

 and the infrasutural rib is less developed and has only few traces of the folds, as the specimens 

 are very young, I think it is not advisable to name or describe them, they may belong to a 

 slight variety of the former. 



I 



15. StLTciila Niersti'aszi n. sp. PI. XXVIII, fig. 6. 



Stat. 271. 5°46'.7 S., 136° o'E. Arafura-sea. 1788 M. Bluish green mud. i Spec. 



Shell broadly fusiform, with rather short spire, thin, light greyish-white. Nucleus wanting, 

 remaining whorls nearly 6, of which the upper one is likewise eroded, angularly convex, slightly 

 excavated below the deep suture. Sculpture consisting of slightly oblique, narrow ribs, arcuated 

 in the excavation, 15 in number in penultimate whorl, with blunt tubercles about the median 

 part of upper whorls and on shoulder of last whorl, with beads at their upper extremities ; 

 just below the suture, the shell is covered with fine growth-striae and spiral lirae, these lirations 

 being faint in the excavation, stronger and crowded in lower part of whorls, more remote on 

 canal; last whorl attenuated below, passing without marked limit in the rather short canal. 

 Aperture oval, slightly angular above, with a rather narrow canal below; peristome broken, 

 according to growth-striae with a very shallow sinus below the suture; columellar margin concave 

 above, directed to the left along the canal, with a thin layer of enamel. 



Operculum thin, corneous, with a terminal nucleus at the left side. 



Alt. 2574, lat. 127,1; apert. alt. 14, lat. 5 Mill. 



Radula with 2 rows of teeth, in about 1 2 transverse rows, each tooth (c) with a rather 

 sharp point and a deep sinus at its basal margin, separating .2 unequal digitations. 



The shell was of rather obscure nature, scarcely any trace of a sinus was visible and 

 if at all by the aid of the growth-lines, it is" very unsignificant, the operculum is not characteristic 

 for the genus; after I had seen the radula, no doubt was left about its belonging to the 7^/^?/rc'/^- 

 midae and by its sinus it nearest approaches Stircttla., though the teeth resemble those of 



64 ■ 



