152 



CENSUS OP DESMIDS OF A TEIASSIC DISTRICT. 



V.C. = Very Common. 0. = Common, 



r. = Frequent. B. = Kare. . V.R. = Very Rare. 



47. P. 



48. P. 



49. P. 



50. P. 



51. P. 



52. P. 



53. P. 



64. 

 65. 



56. 

 57. 



58. 



59. P. 



60. 

 6]. 



Libellula var. interruptum W. 



and G. S. West 

 Libellula var. intermedium Roy 



and Biss. 



Mooreanum Arch. . 

 minutum (Rolfs) Cleeve . 

 minutumi forma major Racib. 

 minutum forma minor Racib. 

 margaritaceum {Ehrenb.) Breb, 



(63m X 12m) . 

 Navicula Breb. 

 Navicula var. crassum W. and 



G. S. West . 

 polymorphum Perty 

 phymatospermum Nordst. 

 spirostriolatum Barker 

 subtile W. and G. S. West 

 truncatum Breb. 

 inconspicuum W. and G. S. West 



Genus Roya W. and G, S. West, 1896. 



62. R. obtusa (Breb.) var. montana 



W. and G. S. West (33m X 6m) . 



63. R. Pseudoclosterium (Roy) W. and 



G. S. West .... 



Genus Closterium Nitzsch. 1817. 



64. C. abruptmn West 



65. C. abruptum var. brevius W. and 



G. S. West . . . . 



66 C. acutum(i'>2/ngrfe.)^re6. (zygospore) 



67. C. acutima var. linea W. and G. " 



West .... 



68. C. aeerosum (Schrank) Ehrenb. 



69. C. angustatum Kiitz. . 



70. C. angustatum var, nov. 



71. C. attenuatum Ehrenb. . 



72. C. Cornu Ehrenb. (97-75m X 8m) 



73. C. Cornu var. nov. 



74. C. calosporum Wittr. (zygospore) 



75. C. costatum Cor da 



76. C. Cynthia De Not. 



77. C. Cynthia var. curvatissimum W 



and G. S. West 



78. C. Dianae Ehrenb. 



79. C. didymotocum Corda 



80. C. Ehrenbergii Menegh. 



