56 SUPPLEMENT TO THE CRAG MOLLUSCA. 
ALVANIA ALBELLA, Leach, M.S. Crag Moll., vol. i, p. 99. Tab. XII, fig. 1 1c. 
Atvanta ALBELLa, S. Wood. Annals and Mag. of Nat. Hist., vol. ix, p. 534, 1842. 
Actis WaLuurt, Jeffreys. Brit. Conch., vol. iv, p. 105, pl. lxxii, fig. 4, 1867. 
Locality. Cor. Crag, Sutton. 
This species was given by me in my catalogue in the ‘ Annals and Mag. of Nat. 
Hist.,’ for 1842, under the name aldella, a manuscript name of Dr. Leach for the 
recent shell since called Walleri, which, as stated at p. 99 of the ‘ Crag Moll.,’ I found on 
a tablet in the Brit. Museum, with the name in Dr. Leach’s handwriting attached. ‘This 
tablet, I regret to say, cannot now be found, and some confusion has arisen in conse- 
quence, as Mr. Jefireys appears to think (‘ Brit. Conc.,’ vol. iv, p. 104) that adbella of 
Leach was ascaris of Turt. Mr. Jeffreys recognises Walleri in a single specimen in my 
collection in the British Museum, but there are twenty-six specimens there on a separate 
tablet which appear to me identical in all respects with some specimens of his recent Waller 
which he kindly gave me. [| fell into the mistake in the ‘ Crag Moll.’ of supposing this 
to be an eroded form of the shell there described as ascaris (supranitida), but I have now 
reverted to my more correct views of 1842. Since my collection went to the British 
Museum, both this shell and swpranitida have become extremely rare in the Crag. 
Some Conchologists have adopted the name of Aclis for this genus, and it may 
require a remark from me in explanation for not following the same plan. In the 
first place [ used the name of Alvania in 1842, when the Crag shell was fully described, 
and this was previous to the name of Aclis, proposed by Dr. Lovén in 1846. In the 
second place I merely employed a name that had been given by Leach, and attached by 
him to a specimen in the Brit. Mus. ; and in the third place the shells included under the 
name of Alvania, by Weinkauff and others, have no characters by which they could be 
distinguished generically from those called Réssoa. 
MENESTHO, Moller, 1842. 
Diagn. Gen. “ Animal pede elongato, angusto, ore simplici, membrana linguali 
destituto ; tentaculis breviortbus, crassiusculis, oculos perparvos ad basin internum ferentibus. 
Operculo pauco-spirato. Testa conica turrita.’—(Moll.) 
The above is a description of this proposed genus, and the author has referred to 
Lurbo albulus of the Fauna Greenlandica, as his intended type, the shell of which presents a 
different form of aperture from either Rissoa or Turritella, and approaches nearest to 
Pasithea, Lea.; but we do not know the species intended as the type of this latter genus 
in which several very different forms have been included. 
