20ft 



7. ? Gemiiwlla interrnpta Turp, Mem. 1. c. f. 24, Ktz, I. e. 

 p. 83. 84. 



Obs^ Biddnlpbia pulchella et obliqnata Gray^ australis 

 Montagne et anrita Br^b. ad Diatomeas spectant. 



B) MEMBRANULA HYALINA INSIDENTES. 



IIT. Scenedesmus Mej/en J celliilae fnsiformes, elliptieae 

 vel laaalatae, lateraliter in seriem teuiaeformem uoiqam rel 

 doplicem dispositae. 



Celliilae Iransversim in seriem planam distribiitae nam- 

 qnam.filnm conferroideam qaemadmodam in generibus snpe* 

 Tins allatis constitiinnt, Nnmero qnidem Tariant, limitibus 

 tamen saepe inter nameros pares definilis. Forma ceilnlarnm 

 extremarnm, a caeteris plernmqne diversa, fines frondis indi- 

 cate et errores a portinncnlis earnndem^ frequenter ocnlis ob- 

 cnrsantibns ritat. Membranula hyalina cni cellulae insident 

 difficillime Gonspi<^a ibique tantum nbi cellnlae ipsae invicem 

 spatiolo separantur. Distribulio ceilnlarnm constantissima et 

 characteristica, forma in speciminibas bene erolatis pro una-^ 

 qaaqoe specie semper eadem; magnitndo varia inter linufes 

 ommbns fere speciebna communes a 0,00001 ad 0,00002, in 

 nnica tantnm snmmopere minor. Endoc^romnm de&nita for- 

 ma gflindere bucnsqne non patuit, resicnlasqne diaphanas in 

 plerisqne speciebns conspicnas , gnttnlas oleo$^ , cellnlasye 

 gastricas ab aliis nnncnpatas, qua numero et disiribntione 

 rarias^ characteres specificos minus aptos snppeditare ceiisni. 

 ]N^omen Scenedesmns antiqnins nnllnmque errorem inclndens 

 prae novo a cl. Ehrenberg proposito servandnm esse bob 

 dnbitaTi, 



1. Scenedesmns quadricauda Br4bwy celluHs oblongis Mnis 

 nsqne denis, mediis fusiformibus, apice rotnndatis, extimi^ 

 Tentrieosis apiceaeotis cavdatis, euidis dirersenlibaSy ii^ 

 seriem simplicem dispositis. — BribA I. c. p. 66* ^ S. 



