ANIMAL NATURE OF DIATOME^!. 441 



Schizonema bombycinum, Kiitz., (Micromega.) 

 Schizonema patens, Kiitz., (Micromega.) 

 Schizonema Jlagettiferum, Kiitz., (Micromega.) 

 Schizonema lineatum, Kiitz., (Micromega.) 



Kiitzing says the Naviculae are ^ to ^th of a line in 

 length, or 0*0246 to 0'027 millim. The largest of his 

 figifres is 6-5, corresponding to 0'0155. In an authentic 

 specimen from Spalato, with which Kiitzing obliged me, 

 and in the corresponding ones from Zara, collected by 

 Sandri, the extreme length of the Naviculse is O02, 

 and the greatest breadth of the primary surfaces is 

 0-0047 millim. 



Schizonema floccosum, Rudolph, (not Kiitz.) 



The length of the Naviculse indicated by Kiitzing is 

 ^th of his line, or 0'045 millim. In specimens collected 

 in Dalmatia by Vidovich, which correspond with the 

 description, the greatest length of the Naviculae is 0'046, 

 the breadth of the primary surfaces 0*005 millim., in single 

 individuals ; the breadth of individuals very near a state 

 of duplication was almost double, and that of the se- 

 condary surfaces, which are elliptico-rhomboidal, O'OOO. 

 In this very distinct species the extraordinary thickness 

 of the partial tubes is remarkable ; they are often more 

 than double the breadth of the Naviculae. 



Schizonema hyalinum, Kiitz., (Micromega.) 



The length assigned by Kiitzing is ^ to ^th of a line 

 = 0-041 6 to 0-0338 millim. The greatest length, in plate 

 xxiv, is represented (^) 7'5, or 0-0179'", and the greatest 

 breadth, in plate xxv, 1*5, or 0'0036 millim. In numerous 

 specimens from Dalmatia, transmitted to me by Vidovich, 

 and corresponding perfectly to the descriptions and the 

 figures, I find the greatest length 0'034, and the 



