240 NATURAL HISTORY OF OUR SHORES 



lines on the surface, each cluster of about the size of a 

 walnut. These are Fragarimn elegans (the generic name, 

 applied from their resemblance to a strawberry). 



In August and September this species is in reproduction 

 that is, in its sexual reproduction and a lump treated as 

 described for the last will reveal not only the adult in- 

 dividuals but large numbers of the tadpole larvae, which 

 will swim actively. in the saucer. The diagram of ascidian 

 tadpole (Fig. 102) is taken from this species. 



There are many allied forms, but those just described 

 are common, and are typical. 



The familiar " Starry Botryllus " can be seen at the 

 same zone as these, but they are more abundant lower 

 down in tide range, 



There is an endless variety of these, but whether each 

 difference represents a species, or whether some are only 

 varieties of the others, I am not competent to say. 



In Giard's beautiful monograph, "Les Ascidies Composees," 

 there are numerous enlarged and coloured figures for the 

 determination of the different species, but the number 

 there figured falls far short of actuality. 



In the genus Botryllus the individuals are small, not 

 more than a quarter of an inch long, and they are arranged 

 in more or less perfect circles, with their mouth openings 

 outward, forming a star-shaped pattern, and these " stars " 

 are closely set in the general investing matrix, which is the 

 common " tunic." 



Each of these little individuals has the same structure 

 as the large ascidians, only that they have their exhalant 

 apertures towards the inner end, as regards the star, 

 where they join into one common Cloaca, which is the 

 centre of the star. 



The most abundant species is Botryllus violaceus. This 

 forms large patches on the sides of, and underneath, boulders, 

 often six or eight inches across. These patches resemble 



