Post-Pleiocene Deposit on Gardiner's Island. 149 



Helicopsyche Shuttleworthi I perceived no opercula ; they bad proba- 

 bly fallen off, or perhaps weie not formed when these sacs were col- 

 lected." 



Yon Siebold gives figures . (referred to in the note above 

 quoted) of the caterpillar-sacs of Psyche Helix and Psyche 

 Planorbis, of the sac of Htlicopsyche Shuttleworthi and of 

 Valvata arenifera, enlarged and copied from Lea. To the 

 "Explanation of the figures" Yon Siebold adds the following 

 supplementary observation : — 



" At my last visit to Zurich I saw in Bremi's collection the cases of a 

 third larger species of Helicopsyche, which Bremi obtained from Shut- 

 tleworth, and bas named Htlicopsyche Colombiensis. Tbese cases come 

 from Puerto-Caballo ; they have a transverse diameter of 1 , 8 q lin., and 

 a height of 1 T 2 „ lin. Rhenisb, and are manufactured out of compara- 

 tively very coarse, rusty-brown stones. With regard to Helicopsyche 

 Shuttleworthi, Bremi informed me, that the cases of this Pbryganidous 

 insect have now been found also on the Lake of Geneva." 



The cases received from Mr. Rousseau, and from Canada, 

 are in size, form, and construction somewhat similar to those 

 figured by Yon Siebold as Helicopsyche Shuttleworthi. In the 

 operculum of the Troy specimens there is the longitudinal 

 opening described by Shuttleworth. 



'XNTL.— Notice of a Post-Pleiocene Deposit on Gardiner's 

 Island, Suffolk Co., ~N.Y. 



By Sanderson Smith. 

 Bead May 1, 1865. 



This deposit was visited by me three or four years ago, but 

 as I was able to spend only about twenty minutes at the loca- 

 lity, I have hitherto refrained from publishing my account of 



