Praeger — On Types of Distribution in the Irish Flora. 29 



to render theii- separation necessary. These are mostly calcicole or 

 calcifuge species, which increase in abundance in the centfe or round 

 the margin according to their proclivities. 



As regards the plants of General type which ai'e not universal. 

 In some cases the gaps in range are with little douht only apparent ; 

 this applies particulai'ly to critical species, such as the two whose 

 distribution is illustrated below (figs. 15, 16). 



Fig. 15. — Viola Reichenbachiana. 



Fig. 16 — Raminculics heteropkyllus. 



But many other cases are instances of genuine discontinuous 

 distribution ; four good examples are illustrated below, all being 

 well-known and easily recognized species (figs. 17-20). 



1-. — Hypopithys multiflora. 



Fig. 18. — Liiiana repens. 



