296 



rita salmonaceo-purpurea. Long. If; alt. 1|-; lat. | poll. Hah. 

 Manila. 



Much like U. Bengalensis and XJ.foliaceus. In the former, 

 both ends of the ventral margin are angular, the posterior side is 

 dilated and angular at tip, and the interior is less bright red. 

 The form of this is rather elliptical than ovate. U. foliaceus is 

 smaller, thinner, compressed, and has a plumbaginous nacre. 



Unio dorsuosus. T. transversa, retrorsum ampliata, inequi- 

 lateralis, compressa, castanea ; latere antico circulari ; latere 

 postico oblique rotundato ; margine dorsali recto ; umbonibus 

 pro-eminentibus, antrorsum concentrice costato-undulatis, retror- 

 sum nodoso-fluctuatis : dente cardinali perobliquo, elongate, 

 compresso ; dente laterali recto : margarita ex albo-ccsrulescens, 

 livido ad umbones tincta. Long. H; alt. |-; lat. ^ poll. Hob. 

 Eastern Asia ? 



Allied to TJ. Murchisonianus, Lea ; it is more widened poste- 

 teriorly, more compressed, not sinuate beneath, thinner. 



Dr. Burnett read a paper on Vibrios, the purport of 

 which was to show that these organisms are plants and 

 not animals, as they have been heretofore considered. 



Dr. Burnett's observations were made with a powerful micro- 

 scope, manufactured by Spencer, of Canastota, New York, which 

 has never as yet been surpassed in power. With the aid of this 

 instrument he had been able to watch the development of Vibrios, 

 of the genus Spirillum. Hitherto, from their motion and the 

 linear direction of the articulations of which they are made up, 

 they have been regarded as animals. Dr. Burnett, however, 

 had been able to detect branching forms, like those of Algse, 

 indicating their compound cell-plant structure. Ehrenberg sup- 

 posed that the Vibrios multiply by fissuration of previously exist- 

 ing forms ; but with his more powerfuj means of observation, 

 Dr. Burnett had seen the pushing out of one cell from another 

 with their gradual increase in size, and he was led to infer that 

 their growth was like that of Torula, by putting forth buds. The 

 ditFerent species of Vibrios seem to be only different stages of 

 development of these Algse. 



