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Var. y. Testd purpurascente, maculis albis nigro sagittatis et zonis 
nigris albo-articulatis ornatd. 
Var. 6. Testd rubicundd, punctulis albis, antice obsolet? purpureo- 
nigrescentibus, antice marginatis marmoratd ; labro crassiore. 
Long. 0°36 ad 0°40; lat. 0°44 ad 0°48; conv. 0°32 poll. 
Hab. Sual, province of Pangasinan, isle of Lucon: in a small 
stream. 
Operculum of a Clithon, yellowish white, marked with a fine cir- 
cular streak in the centre: two teeth at the summit of the interior 
face; the upper one short, yellow; the lower one circular, yellow, 
striated lengthwise and across, sometimes dilated at the summit ; 
the intermediary plate between the two teeth of a whitish colour. 
Mr. Yarrell exhibited some coloured plates of a large work on the 
Mammalia of North America, by Mr. Audubon and Dr. Bachman. 
