190 



River.* Mr. Heckelt had placed it in his genus Trachidermis, 

 where I do not believe that it can remain, notwithstanding its 

 rough skin and its teeth on the palatine bones. Dr. Richardson 

 has felt the necessity of withdrawing it from the genus Cottus. 

 In the " Fauna Boreali Americana," he thought the genus 

 Hemilepidotus might perhaps receive it, but he himself has 

 acknowledged since, that its place was not there, and when 

 establishing the genus Centrodermichthys, j: for some species of 

 the China seas, he proposed to associate with them the C. asper. 

 Not having at my disposal sufficient materials to satisfy myself 

 upon this subject I shall reconsider it in a monograph of the 

 species of Cottus of North America, which I am now engaged 

 in preparing. 



Dr. Gould presented, in the name of Capt. Joseph P. 

 Couthouy, a specimen of Volcanic Ammonia, brought 

 home from the United States Exploring Expedition. 



Rajinder Datt of Calcutta was chosen a Corresponding 

 member of the Society. 



November 7, 1849. 

 The President in the Chair. 



Present, twenty-nine members. 



Present, by invitation, M. H. Perley, Esq. of New 

 Brunswick. 



Prof. Agassiz said that he had been for some time en- 

 gaged in the study of the Worms of the coast of Massachu- 

 setts, and he had obtained some very interesting results. 



He had found that in many of the Annelids which, at an early 

 stage of their development are furnished with a pair of eyes to 

 each ring, these organs gradually disappear, so that at maturity 



* Faun. Bor. Amer. in. 1836, p. 295, PL 95, fig. 1. 

 t Ann. d. Wien. Mus. ii. 1837, p. 162. 

 t Ichthyology of the " Sulphur." 



