66 



Bankivia, Beck, 1848 (Krauss, Sudafr. Moll.)* The 

 retention of this shell (for there is only one very variable 

 species) in a distinct genus from Elenchus is hardly 

 desirable. Messrs. Adams rely on the twisted columella, 

 and the non-nacreous shell ; but the shell is nacreous, though 

 only faintly perceptible, and the nacre has a rosy tint. 



Tegchocochlea, Klein, 1753 (Tentamen methodi ostraco- 

 logica 4 B., p. 43). I have given a notice of the genus in 

 the Proc. Linn. Soc, N.S.W., vol. 2, p. 89. I do not think 

 that Klein should have the credit of this genus, as Messrs. 

 Adams' definition in no way agrees with his, which would 

 include nearly all our Trocliidce. The following is Klein's 

 definition : — TrocJio-cochlea est cochlea jper modum troclii, 

 conice turhinata sed in ultima sjpira ventricosa, os laterale 

 deducens nee cochlea sine magna inclinatione qneat inniti. 

 Wheel- shell — a shell which is like a wheel, turbinately 

 conical, but in the lower part of the spire ventricose, causing 

 a lateral mouth, so that the shell cannot stand without being 

 greatly inclined. This definition would apply to one-fourth 

 the known univalves, and cannot be said to apply to one 

 more than another of our Australian turbinated genera.f 

 The authors of the " Genera" give a good many synonyms, 

 but only some of them, or perhaps none of them, agree with 

 their definition. Take, for instance, Gray's (not Oken's) 

 Lahio. In this the axis is perforate. The fact is the name 

 — a very awkward name — is Klein's, and the genus is that of 

 Messrs.* Adams. They define it thus : — " Shell solid, conoidal, 

 imperforate in the adult, whorls smooth, or transversely 

 Urate, the last rounded at the periphery aperture nearly 

 rhomboidal, columella thick and rounded, ending anteriorly 

 in a slightly prominent tubercle." Limited thus, I think the 

 genus is a good one for Australian forms. 



MoNiLEA, Swainson, 1840 (Shells and Shell-fish, part 2, 

 p. 352) " umbilicus deep and wide, but the edges quite 

 smooth, with a thickened half margin formed by the inner 

 lip, which terminates abruptly." In this genus the 

 umbilicus is furnished with a thick spiral callus dilated 

 anteriorly where it joins the excavated columella, and with 

 another striated spiral callus more external, which ends 

 anteriorly in a pointed tooth. The Australian species seem 



*So Carpenter in Maz-shells. I have not Ivi'auss' work by me now to 

 refer to for Beck's definition. 



tThe whole system of Klein is curiously clumsy, and often leads to two 

 or three appellatives. I regret not being able here to give a more 

 lengthened notice of its peculiarities. 



