PLATE IV. 



Thalassina scorpionoides, branchiae (p. 19). 



Fig. 1. Pereion, showing the form and arrangement of the branchiae : lateral wall of 

 the carapace removed. 



,, h. First gnathopod with rudimentary mastigobranchia, with podobranchia and 

 arthrobranchia attached ; h", arthrobranchial plume (detached); enlarged. 



,, i. Second gnathopod with rudimentary mastigobranchia, with podobranchia 

 attached ; i", arthrobranchial plume detached, showing the under side ; 

 enlarged. 



„ k. Coxa of first pereiopod with rudimentary mastigobranchial lash, with the 

 podobranchial plume attached ; k", anterior arthrobranchia detached, 

 showing under side ; k'", posterior arthrobranchia, showing upper surface ; 

 k"", under surface of the base of the same ; enlarged. 



