WISCONSIN PHYTOPLANKTON 129 



base. Although the genus is provisionally placed in the Micractinieae 

 its spines are quite different from those of other genera of the sub- 

 family. 



LAGERHEIMIA Chodat 1895. 



Cells solitary; ovoid, ellipsoid, or citriform. Cell wall firm, without 

 a gelatinous sheath; with long tapering setae that lie a short distance 

 back from the poles or cover the entire wall. Chloroplasts 1-4, pari- 

 etal, laminate ; with or without pyrenoids. 



Eeproduction by autospores that are generally liberated at once but 

 which may remain inside the old mother wall a short time. 



KEY TO THE SPECIES. 



Setae covering entire cell wall L. DROESCHEM 



Setae confined to poles of the cell. 



Cells lemon-shaped L. CITBIFOBMIS 



Cells ovoid. 



Length of setae more than double that of cell L. LONGISETA 



Length of setae less than double that of cell. 



2-4 setae at each pole L. SUBSALSA 



3-8 (generally 6) setae at each pole L. CILIATA 



LAGERHEIMIA CILIATA (Lagerheim) Chodat. PI. 31, Figs. 1-2. 



Nuova Notarisia 10: 90. 1895. 



Oocystis ciliata Lagerheim, ofvsers Kgl. Vet.-Ak. Forh. 39, No. 2: 76, pi. 3, 

 figs. 33-37. 1882. 



Chodatella ciliata (Lag.) Lemmermann, Hedwigia 37: 310. 1898. 



Cells oblong-ovoid, with 3-7, hyaline, delicately tapering setae at 

 each pole. Chloroplasts 1-4, parietal, laminate; each with a single 

 pyrenoid. ( Euplanktont) . 



Breadth of cells (without setae) 6-18 p; length (without setae) 10- 

 21 p. Setae 15-20 p long. 



Kegonsa (IT), Mendota (sss). 



The setae of this species are not in definite whorls but distributed over 

 the entire polar region. 



var. minor (G. M. Smith) comb. nov. PI. 31, Fig. 3. 



Chodatella ciliata var. minor G. M. Smith. Bull. Torr. Bot. Cl. 43: 477, 

 pi. 25, fig. 16. 1916. 



Cells ovoid, with 6-8 setae at each pole. (Euplanktont). 

 Diam. cells (without setae) 6-7.5 p; length (without setae) 8-10 p. 

 Setae about 20 p long. 

 Muskallonge (rr). 



9 



