230 Bacillarierc, Naviculaceae, Staurosigma. 



rigida Kuetz (quae Niizschiam sistit) firmior et pro ratione an- 



gustior est. — Ad revera Nitzschia.? 

 3. Okedenia? Cretae (Ehr.) D. T., Amphipleura Creire Grun. in Wien. 996 



Verhandl. 1862 p. 468, Eunotia Creicc Ehr. Mikrog. t. XXII, f. 55- 



56. — Valvis leniter arcuatis, dimidiato-laoceolatis, striis distinctis; 



facie connectivali oblonge obtuseque lanceolata. 



Hab. fossilis ad « Caltanisetta » Siciliae (Ehrenberg). 



STAUROSIGMA Grun. [1860] in Wien. Verhandl. X, p. 567 (Etym. 

 stauros crux et sigma littera S), De-Toni Osservaz. tasson. Bacill. 

 p. 896. — Valva? genuinse Stauroneidis sed rhaphe sigmatoidea; 

 frustula a facie connectivali visa recta (nec arcuata). 

 Obs. Generi Rhoicosigmati peraffine. 



A. Species fossiles. 



1. Staurosigma Ehrenbergii Grun. in Wien. Verh. 1860, p. 567, Stau- 997 

 roneis Sigma Ehr. in Abh. 1844, p. 88, Mikrogeol. t. XVIII, f. 63. 

 — Habitu et magnitudine Pleurosigmatis acuminati; valvis 110 

 [x. longis, stauro distincto biovoideo, valvas latitudinem totam non 

 percurrente. 



Hab. fossile ad «Richmond» Americse borealis (Ehrenberg); 

 vivum in portu «Yokohama» Japoniaa (Tempere, Brun). 



2. Staurosigma asiaticum Temp. et Brun Diat. foss. du Japon p. 56, 998 

 t. 9, f. 1. — Valvis longe sigmoideis, acuminatis, 190-220 s 25-28, 

 stauro valde conspicuo; sulcis duobus in utroque latere rhaphes 

 prsesentibus, valva ergo in 5 compartimenta divisa; striis trans- 

 versis parallelis, levibus, eequidistantibus, 16-18 in 10 u.., prope 

 rhaphen attenuatis; striis obliquis nullis; facie connectivali recta. 



Hab. fossile in calcaria « Sendai » Japoniae, sat frequens. 



B. Species aquse marinse incolae [Cfr. etiam Staurosigma Ehrenbergii]. 



3. Staurosigma obliquum (Greg.) Rabenh. Fl. Eur. Algar. I, p. 253, 999 

 Stauroneis obliqua Greg. Micr. Journ. IV, p. 10, t. I, f. 35, Pritch. 

 Inf. p. 911, t. VII, f. 63. — Valvis subrhombeo-oblongis vel rhom- 

 beo-sublanceolatis, 25-65 fx. longis, apicibus subacutis vel subob- 

 tusis, area transversa lata valvarum marginem attingente; striis 

 transversis divergentibus, subtiliter punctatis, rhaphen attingentibus, 

 18-20 in 10 v.. 



Hab. ad oras Scotiae, Hibernice (Gregory), in mari mediter- 

 raneo (L. Rabenhorst). 



