176 CONJUGATEiE. 



15. STAUROCARPUS. 



Char. Sporangium either square or cruciform, and lodged in 

 the transverse tubes. 

 Derivation. From aravpos, a cross, and Kapiros, fruit. 



" Certain square or cruciform species of conjugating Con- 

 ferva were doubtfully associated by Agardh with the genus 

 Mougeotia ; these species I learned long since had been sepa- 

 rated from it by Mr. Shuttleworth under the appropriate 

 generic appellation of Staurocarpus. Mr. Shuttleworth how- 

 ever did not, so far as I can learn, publish his opinion of the 

 propriety of establishing for these curiously formed species a 

 distinct genus, contenting himself with communicating his 

 views to some of his correspondents, of whom I may name 

 the following as being conversant with those views : — Mr. 

 Borrer, the Rev. M. J. Berkeley, and Mr. Ealfs. Within 

 these few days I have been informed by Llr. Berkeley that 

 Kiitzing has proposed this genus under the term of Stauro- 

 spermum in a sketch of" a work on the Algce, inserted in the 

 first number of the new series of " Linna^a." No account of 

 the genus is given by Kiitzing, but merely the name and an 

 enumeration of species belonging to it. Mr. Shuttleworth's 

 appellation I conceive to be much more appropriate and ac- 

 curate than that of Kiitzing, and have therefore ventured to 

 retain it ; for the word Staurocarjms applies to the fructifica- 

 tion generally, which is either square or cruciform, while 

 Staurosj^ervmm appears to me to specify the reproductive 

 granules or zoospores themselves with Avhich each sporangium 

 is filled, and which are more or less of a circular form." — 

 Hassall, in Annals of Nat. Hist. 



That Agardh entertained a very strong suspicion that the 

 square-fruited species ought to be separated from the genus 

 Mougeotia, will be apparent from the following observa- 

 tions : — 



" Ceterte species quoad fructum non satis coguitfe, et 

 postea forsan separaudje, hue tantum ob habitum retentte." 



The genus Staurocarpus differs from Mougeotia in the facts 

 of the transference of endochrome and formation of sporangia, 



