BY R. TATE AND W L. MAY. 459 



RissoiA TUMiDA, Teii.-Woods (Diala). 

 Dlala fumida and Rissoia Kersliawi are certainly the same by 

 comparison of authentically named specimens. The species is 

 closely related to R. olivacea and R. Frauenfeldi; the ornament 

 is like the latter, but the shell is smaller and not so stumpy and 

 the whorls are flat. Brazier referred Diala tumida to R. olivacea; 

 but unless R. olivacea and R. Frauenfeldi are the same, then R. 

 tumida is a distinct species. The reference by Brazier of R. 

 Diemenensis, Petterd, to R. olivacea is confirmed. 



RissoiA DissiMiLis, Watson {Eiilima). 



The reputed type of Eulima Tasmanica, Ten.-Woods, in the 

 Hobart Museum is a Rissoia, perhaps a large and white specimen 

 of R. cyclostoma as has been suggested ; but " its somewhat 

 depressed form," to use the author's phrase, does not apply to R 

 cyclostoma, though it does to Rissoina cylindracea, Ten.-Woods, 

 a Port Jackson shell which one of us has recently renamed 

 Rissoia ischua; but as suggested by Mr. Hedley, the species is 

 already known as Eulima dissimilis, Watson, also a Port Jackson 

 shell. Eulima eurycliades and Mucronalia ccantliias, Watson, 

 should be transferred to Rissoia. Eulima Tasmanica has priority 

 of publication, but the specific name has been virtually pre- 

 occupied in Rissoia; cylindracea has previously been used, so 

 that Watson's specific name of dissimilis should be adopted. 



R. dissimilis, R. Verconis and R. Simsoni are closel}'- related; 

 R. Verconis is much smaller than R. dissimilis, is margined at the 

 anterior suture, which is deeply channelled; R. Simsoni is more 

 ■cylindroid and is much larger than R. dissimilis. 



Rissoia Mari^, Ten.-Woods. 



This species has been somewhat generally but erroneously 

 attributed to Diala semistriata, to wiiich it has some resemblance* 

 but is more elongated, with convex whorls, has a complete peri- 

 stome, and the base is smooth (not striated as is usual with D. 

 semistriata). R. Marice is not infrequently of a uniform dark 

 colour. It occurs in S. Australia (R. Tate) and in Victoria (J. 

 H. Gatliff !). 



