1902.] VARIATION IN THE NORWAY LOBSTER. 3 



of frequency of these arrangements, it will be convenient to 

 describe each of them separately. They are as follows : — 



A. The normal arrangement. 



B. The normal apertures and two additional ones at the 



bases of the fourth legs, making a total of four 

 apertures. 



C. The normal apertures and an additional one at the base 



of the left fourth leg, making a total of three apertures. 



D. The normal apertures and an additional one at the base 



of the right fourth leg, making a total of three 

 apertures. 



E. The normal apertures and four additional ones on the 



third and fourth legs, making a total of six apertures. 



F. The normal apertures and three additional ones on the 



fourth legs and the left third leg, making a total of 

 five apertures. 



G. The normal apertures and three additional ones on the 



fourth legs and the right third leg, making a total of 



five apertures. 

 H. The normal apertures and two additional ones on the 



left third and left fourth legs, making a total of four 



apertures. 

 K. The normal apertures and an additional one on the left 



third leg (there being a gap in the series), the total 



number of apertures being three. 

 L. The normal apertures and two additional ones on the 



right third and left fourth legs, the total number of 



apertures being four. 

 M. The normal apertures and five additional ones on the 



fourth and third legs and also on the left second leg, 



the total number of apertures being seven. 



These arrangements may be represented graphically as f oUows : — 



B. C. D. E. 



r. I. r. I. 7\ I. r. I. 



Third legs. . . 



• Fourth legs. • • . 

 Fifth legs. • • . • . 



F. G. H. K. 



r. I. r, I. r, I. r. I. 



Third legs. 

 Fourth legs. 

 • • • Fifth legs. • • . . 



L. M. 



r. I. r. I. 



Second legs. • 



. Third legs. • 



• Fourth legs. 

 Fifth legs. 



[The letters r. and I. denote the right and left sides.] 



1* 



