THE NAUTILUS. 



VOL. XI. JUNE, 1897. No. 2. 



HELICINA DYSONI 



BY CHARLES T. SIMPSON. 



While collecting shells in the Island of Utilla, on the north coast 

 of Honduras, I frequently visited a Brickly Thatch palm grove 1 

 which lay on the south shore. The Brickly Thatch is a curious, 

 small palm, with straight, slender stems, a little larger than one's 

 wrist, and about twenty feet in height, surmounted by a crown of 

 shining, fan-shaped leaves. The bases of these trees are slightly en- 

 larged, and they stand on a cone of stilted roots, which, with the 

 soil and rubbish among them, fill the conical space almost solid. 

 They grow thickly to the exclusion of all other vegetation, and the 

 curious bunches of roots completely fill the space on the ground and 

 make it quite difficult and awkward to get around. Under the al- 

 most twilight of this dense copse I found excellent collecting, and I 

 there discovered Colobostylus andreivsce, Cylindrella bourguignatiana 

 and several other new species. Among other shells I kept finding 

 specimens of the pretty little Helidna dysoni, but always dead and 

 generally faded. An enterprising collector is never satisfied with 

 dead shells, and I searched everywhere to find this rnollusk alive 

 under the dead, fallen palm leaves, in what rubbish lay around, on 

 the stems of the palms, and among their tough, matted roots but 

 in vain, and I finally concluded that the colony, of which these were 

 remnants, had either died out or migrated. 



One day I visited a part of the grove that I had not seen before* 

 a spot at its edge, and here I found a single living tree which had 



1 Thrinax radiala. 



