113 



the fully formed larva is that shown in PI. XV, Fig. 4, with only two 

 arms, the postoral ones, which are fairly long, about body length. There 

 is, however, a considerable variability in the larval shape; another pair 

 of arms, the posterodorsal ones, may develop, but sometimes only one of 

 these arms is formed. Also the arms may coalesce to a various extent. 



Fig. 47. Various forms of the larva of Peronella Lesueuri. ""A. Only in one of them the 

 young spines are drawn; all the specimens figured were at about the same stage of develop- 

 ment. Drawn from life. 



Thus the variation as regards the larval shape is rather phantastic, as seen 

 from the sketches represented in figure 47. And these larvae could not be 

 designated as abnormal, since the metamorphosis was completed by all 

 of them, even by the one with no arms at all. Also among the larvae reared 

 by Tennent corresponding variations occurred, even a specimen with 

 five arms, which I have not observed. On account of the rudimentary 

 character of the larva these variations are not very surprising; possibly 



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