Sketch of the Infusoria of the family Bacillaria. 285 



shall merely refer to them by the numbers given to the figures 

 representing them. I hope that these figures will enable some of 

 the learned students of this family in Europe to decide which 

 species are new, and perhaps if this paper should meet the eyes 

 of Ehrenberg, he may oblige us by furnishing for this Journal 

 the authentic names of the species I have represented in the ac- 

 companying plates. 



For what relates to the classification and synonymy of this 

 family I am chiefly indebted to an abstract of Ehrenberg's work 

 on Infuriosa, which is appended to Mandl's Traite pratique du 

 Microscope. The generic and specific characters which I give 

 are in most cases literal translations from this work. I have 

 also studied with much profit Kutzing's Synopsis Diatomearum, 

 in the Linncea for 1833. The plates accompanying Kutzing's 

 memoir have decided many doubts for me. Ehrenberg's great 

 work on Infusoria I have not yet seen. 



Without further preface, I shall now present a translation of 

 Ehrenberg's characters for the family 



BACILLARIA. 



" Polygastric (distinctly or probably*) without intestinal canal ; 

 appendices (distinctly or probably) variable, undivided, body mul- 

 tiform ; carapace often prismatic and siliceous, with one or seve- 

 ral openings, often having the form of articulated polypidoms, in 

 consequence of imperfect, spontaneous (longitudinal) division." 

 Ehrenberg divides this family into the following groups, viz. 



Desmidiacea, having the carapace simple, free, and univalve, 

 (not usually siliceous.) 



Naviculacea, with the carapace simple, free, with two or more 

 valves, (siliceous.) 



Echinellea, with the carapace simple, fixed, (siliceous.) 



Lacernata, with the carapace double, (siliceous, and enveloped 

 in tubes or gelatine.) 



He separates the Closteria as a distinct family, but this genus 

 is so closely allied to Euastrum, that I cannot hesitate to follow 

 the example of most writers upon the subject, and to class them 

 with the Desmidiaceae. 



* The question as to the correctness of Ehrenberg's views with regard to the 

 internal structure of his Polygastrica, appears still undecided. 



