Bibliography. 379 



to the enlightened zeal and scientific accuracy of the native-bom band 

 of naturalists, whose united labors have been concentrated in the pro- 

 duction of so brilliant a result. There is probably no country in the 

 world where the familiar knowledge of nature promises with more cer- 

 tainty to become the privilege and enjoyment of the people than in 

 our own, where alone researches of a truly scientific character, are 

 conducted under the eye and with the approbation and support of the 

 people themselves. 



Those who would have a full view of this class of labors, as actually 

 performed in the United States, will find it in Prof. Hitchcock's address 

 before the associated geologists at Philadelphia, and published in the 

 former part of this number. 



Dr. Gould iji the report under notice, has selected the mollusca as 

 the principal field of his labors, both because it is the most extensive 

 and therefore most important, and the one to which his previous re- 

 searches and labors had been more particularly directed, and we may 

 say, the one which his own discoveries had greatly augmented. 



The reader may judge of the extent of Dr. Gould's labors in this 

 department, when he learns that the present history of the testaceous 

 mollusca of Massachusetts, embraces nearly double the number of spe- 

 cies enumerated in the list appended to Prof. Hitchcock's first report, 

 and which was the result of the united contributions of several con- 

 chologists. 



Full descriptions are given in the present report, of two hundred and 

 seventy four species. They are divided into families and groups, ac- 

 cording to the recent views and classifications of the most celebrated 

 malacologists, and each class is introduced by appropriate descriptive 

 remarks. 



The two hundred and seventy four species enumerated, are divided 

 as follows among the various classes : — Annelida, six ; Cirripedes, 

 twelve ; Conchifera, ninety seven ; Brachiopoda, two ; Gasteropoda, 

 one hundred and fifty seven. Of these, twenty nine species are ter- 

 restrial, forty two are inhabitants of the fresh waters, and two hundred 

 and three are marine, beside which there are in addition, seven marine 

 and two terrestrial naked molluscs, or slugs, as they are vulgarly called. 



The value of this work is much enhanced by the accurate although 

 uncolored figures which Dr. G. has drawn, evidently with much labor, 

 of two hundred and thirteen of the species described. Every one who 

 has experienced the difficulty of determining shells from unillustrated 

 descriptions, will fully appreciate the value of accurate figures. 



But there is one point to which Dr. Gould has devoted much atten- 

 tion, and which has claims of interest to all naturalists, especially to 

 geologists, namely, the geographical extent and distribution of the 



