THE AERIAL ALGÆ OF ICELAND 



427 



sporis vel aplanosporis ex contentu cellulæ maternæ per divisiones succe- 

 daneas ortis ruptura membranæ maternæ libcratisque. Fig. 34. 



E. Icel. 79. 



This species shows great resemblance to Myrmecia cjlobosa Printz 

 (1921, p. 14\ Unfortunately it has not been possible, despitc Professor 



Fig. 34. Myrmecia pijrifonnis n. sp. (X 1200). 



Printz's kind exertions, to procure niaterial of M.globosa for comparison. 

 But the description and ligures of this species are so excellent that it is 

 quite possible to draw a comparison. I have only had Myrmecia pyri- 

 formis in the dried condition , but by means of lactic acid, chlor-zinc- 

 iodine, and potassium tri-iodide I have been able to get a fair idea of 

 its cell structure. What was most difficult was to ascertain the form 

 of the chro matophore, I think, however, that it must be parietal, bell- 

 shaped as in M. globosa, but in contrast to the latter it was furnished 

 with a pyrenoid which was very distinctly seen after soaking in warm 

 lactic acid, rinsing with water, and treatment with potassium tri-iodide. 

 Often the pyrenoid seemed to be surrounded with a quantity of starch. 

 Also in a preparation obtained by boiling m 5 p. c. nitrate of silver 



