216 The Botanical Gazette. [April, 
mon inclusions. The body of the specimen was found to 
consist of a plant which could not be satisfactorily deter- 
mined. The material was therefore referred to Dr. Farlow, 
who not only confirmed the observations previously made, 
but ascertained that the dominant species was Dicothrizx Lp- 
sophila (Ag.) B. & Flk. From the facts thus noted the infer- 
ence was drawn that the pebbles might be regarded as verita- 
ble museums which would probably disclose some new form 
each time a fresh examination was made 
More recently some of these pebbles were sent to Mr. E. 
Grove, of England, who in turn transferred them to Mr. 
George Murray, of the British Museum. Mr. Grove under- 
took the determination of the diatoms, and has added con- 
siderably to our knowledge of the composition of these curious 
communal growths, by the publication of a list embracing 
24 genera and 100 species and varieties.2 This somewhat 
acteristics of the pebbles. His determination of the compo 
nents showed that, ‘‘the predominating kind was clearly 3 
species of Schizothrix while mixed with it there were other 
forms, notably filaments of Stieonema and Dicothrix.” 
mass is formed of entangled filaments; they appear to belong 
to a Schizothrix, but which?” Finally he says, ‘‘I do not 
think one can make anything very distinctly out of this spect” 
men except Schizothrix fasciculata, which undoubtedly % 
curs in abundance.”* Excellent figures of this plant are ge 
by Mr. Murray. 5. 
It would thus appear that from two independent meet 
we have results which, while agreeing in many respect . 
? E. Grove.—Diatomaceous remains observed in preparations and washing? 
of calcareous alge. London. 18). 
"ge Murray.—Calcareous pebbles formed by algz. London. 1895. 
