On the French Species o/'Geomalacus. 271 



The absence of all spiral sculpture, and the strong, arcuate, 

 oblique plications or ribs are the chief points of distinction. 



Ahretia hrasiliensis. 



A. testa parva, elongata, polita, saturate castanea, infra sutiiram 

 zona angusta flava ornata ; anfr. 10, primi 2 subglobulares, ca^teri 

 plani, plicis longitudinalilms superne tuberculis flavidis tcrraiiiatis, 

 (in anfr. ultimis cluobus 15, inferno obsoletis) instructi, baud spi- 

 raliter striati ; anfr. iiltimus brevis, subquadratus ; apertura parva, 

 fusca ; columella brevissima. 



Var. omnino flavida. 



Long. 11 mill., diam. 3. 



Hob. Botafogo Bay, Rio de Janeiro (3 fathoms, sandy mud). 

 Collected by J. Macgillivray, Esq., during the voyage of the 

 '■ Rattlesnake.' 



A very distinct species, at once recognized by the smallness 

 of its size, the deep chestnut colour, with the yellow band 

 below the suture, which tints the nodulous ends of the longi- 

 tudinal ribs, and the shortness of the aperture and columella. 

 There is no spiral furrow or depression below the suture. 



XXIX. — On the French Sjjecies of the Genus Geomalacus. By 

 D. F. Heynemann, President of the German Malacozoolo- 

 gical Society, Frankfort-on-Maine. 



Through Mr. T. A. Verkriizen of London I received a small 

 parcel of living Geomalacus maculosus^ Allman, from Ireland ; 

 and having carefully examined these, I am now enabled 

 critically to investigate the statement of several French authors 

 that this genus not only occurs in France, but is there repre- 

 sented by various species. 



English authors started an hypothesis that the animals, with 

 the plants they live amongst (and which are only met with in 

 the south-west of Ireland), were of Asturian or Spanish origin. 



Although it had not been proved that Geomalacus does occur 

 on the Pyrenean peninsula until Lucas von Heyden found one 

 specimen in the Asturias, during his entomological journey in 

 Spain in 1868, and forwarded it to Germany, the above hypo- 

 thesis of British authors was nevertheless adopted in 1867 by 

 the French malacologists Bourguignat and Mabille ; and they 

 even went to the length of taking as an established fact what 

 had been proposed as a supposition only. 



Geomalacus having thus been once established as of Spanish 

 origin, its distribution must, according to the ideas of these 

 authors, have taken place by way of France only. All at 



