studies in Problematic Organisms. 71 



vegetaiix refermes dans les diverses couches du globe." The 

 first volume, bearing date of 1828, treats of cr\ptogams, 

 Algge among them. In his introductory remarks the author 

 says: "We give this name [Algoe] to all the aquatic crypto- 

 gams without articulations that form the two families Ulvacea 

 and Fticacece, families that we have found in many cases diffi- 

 cult to distinguish in a fossil state, their characters being 

 essentially in the arrangement of the reproductive bodies, and 

 in the character of the tissue that composes their fronds, 

 both characters that disappear very soon in fossil plants." 

 He then proceeds to examine the characters of living Algae, 

 noting the distribution of various genera and their characters, 

 but, before taking up the genus Fucoides and the species 

 referred to it, he says : " We have not divided this family into 

 distinct genera, mainly because the proper characters to 

 exactly define them are very rarely apparent, and the classifi- 

 cation can not be a precise one ; but we have divided the 

 general group of fossil Algae, to which we have given the 

 name of Fucoides, into sections founded on the form of the 

 frond, sections that correspond quite exactly with one or 

 more genera of living Algae." 



It is quite evident that Brongniart, while recognizing the 

 diverse characters of the plants, also saw the difficulties in 

 the way of arranging them in a satisfactory manner. The 

 great diversity becomes very evident when the species 

 described are studied in detail. The following is a list of the 

 species in the sections given by the author. The new species 

 are indicated by " n. sp. :" 



I. S.\RGASSITES. 



1. F. septentrionalis, (Ag.) sp. 



2. F. sternbergii, n. sp. — Algacites cau/escms Stern., and 

 F. bohemiciis Stern. 



II. FUCITES. 



3. F. .strictus, Br. 



III. Laminarites. 



4. F. tuberculosus, n sp. 



