The following List of tho Molluscs inhabiting shells, was 

 prepared by Mr. Joseph True of this city. Mr. T. has made 

 most minute observations on the localities and habits of this 

 branch of our local fauna, and it has been deemed advisable to 

 preserve such notices as worthy of one of the objects, which the 

 Essex Institute proposes in the records of the natural history 

 of Essex County. No authorities are given by Mr. T. for his 

 nomenclature, he having used the Report on the Invertebrata 

 of Massachusetts, comprising the Mollusca, &c.j prepared for 

 the State Survey by Dr. A. A. Gould. 



Publication Committee. 

 Salem, 1857. 



Shells gathered about Salem, Mass., by Joseph True, 

 with 'particular localities designated^ and remarks on the 

 species. 



Spirorbis. 



. au 1 1 / Eound on aea-weed, old shells and stones. 

 b. simstrorsa ) ' 



S. spirillum. Found in summer on the smaller sea-weed. 



S. carinata. On old shells and stones. 



Serpula. 

 S. vermicularis. On old shells and wood thrown up from 

 deep water. 



Balanus. 



B. tintinnabulum. On vessels bottoms. A foreign species. 



B. eburneus. A few specimens, near City Mills, not com- 

 mon. 



B. ovularis. Dr. Gould's figure no. 7, I consider the young 

 of rugosus, of one year old or less ; and figure no. 10 is rugo- 

 sus of two years or less. By a careful study of Balanus for 

 twenty years, I have found the species live but two years. 



B. rugosus. Between high and low- water mark, abundant. 



B. elongatus. Found between high and low-water mark. 

 This shell lives only one year. I have found specimens on the 

 bottom of a schooner, 1§ inches long, which grew between Ap- 

 ril 1st and October 15th, her bottom having been painted on 

 the first day of April. 



B. geniculatus. From deep water on shells, decayed wood 

 and stones. 



