lo Stewart, Branchial Lamellae of Ligia oceaiiica. 



EXPLANATION OF PLATES. 



Plate L 



Fig. I. — Transverse section of the third gill of Ligia oceanica 

 in the normal condition. 

 r« = endopodite, ^ = exopodite, <;= peduncle. 



Fig, 2. — Enlarged portion of a T.S. endopodite. 



a = cuticle, /' = nucleated hypodermal layer, t" = lumen. 



Fig. 3. — Enlarged portion of a T.S. exopodite. 



a = cuticle, ^ = cellular tissue of the lamella, r = blood- 

 vessel. 



Fig. 4, — T.S. endopodite of the gill of a specimen kept for 

 four days in sea-water. 



The soft tissue has become stringy, and numerous 

 strands of cytoplasm extend across the lumen. 



